From 1661372c912d1966e21e0cb5463559984df8249b Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 7 Feb 2023 17:06:51 -0500 Subject: [PATCH 01/32] lsm: move the program execution hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 52 ----------------------------- security/security.c | 69 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+), 52 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 6e156d2acffc..784e19fd665b 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,58 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for program execution operations. - * - * @bprm_creds_for_exec: - * If the setup in prepare_exec_creds did not setup @bprm->cred->security - * properly for executing @bprm->file, update the LSM's portion of - * @bprm->cred->security to be what commit_creds needs to install for the - * new program. This hook may also optionally check permissions - * (e.g. for transitions between security domains). - * The hook must set @bprm->secureexec to 1 if AT_SECURE should be set to - * request libc enable secure mode. - * @bprm contains the linux_binprm structure. - * Return 0 if the hook is successful and permission is granted. - * @bprm_creds_from_file: - * If @file is setpcap, suid, sgid or otherwise marked to change - * privilege upon exec, update @bprm->cred to reflect that change. - * This is called after finding the binary that will be executed. - * without an interpreter. This ensures that the credentials will not - * be derived from a script that the binary will need to reopen, which - * when reopend may end up being a completely different file. This - * hook may also optionally check permissions (e.g. for transitions - * between security domains). - * The hook must set @bprm->secureexec to 1 if AT_SECURE should be set to - * request libc enable secure mode. - * The hook must add to @bprm->per_clear any personality flags that - * should be cleared from current->personality. - * @bprm contains the linux_binprm structure. - * Return 0 if the hook is successful and permission is granted. - * @bprm_check_security: - * This hook mediates the point when a search for a binary handler will - * begin. It allows a check against the @bprm->cred->security value - * which was set in the preceding creds_for_exec call. The argv list and - * envp list are reliably available in @bprm. This hook may be called - * multiple times during a single execve. - * @bprm contains the linux_binprm structure. - * Return 0 if the hook is successful and permission is granted. - * @bprm_committing_creds: - * Prepare to install the new security attributes of a process being - * transformed by an execve operation, based on the old credentials - * pointed to by @current->cred and the information set in @bprm->cred by - * the bprm_creds_for_exec hook. @bprm points to the linux_binprm - * structure. This hook is a good place to perform state changes on the - * process such as closing open file descriptors to which access will no - * longer be granted when the attributes are changed. This is called - * immediately before commit_creds(). - * @bprm_committed_creds: - * Tidy up after the installation of the new security attributes of a - * process being transformed by an execve operation. The new credentials - * have, by this point, been set to @current->cred. @bprm points to the - * linux_binprm structure. This hook is a good place to perform state - * changes on the process such as clearing out non-inheritable signal - * state. This is called immediately after commit_creds(). - * * Security hooks for mount using fs_context. * [See also Documentation/filesystems/mount_api.rst] * diff --git a/security/security.c b/security/security.c index cf6cc576736f..1e7dbaf9ad28 100644 --- a/security/security.c +++ b/security/security.c @@ -6,6 +6,7 @@ * Copyright (C) 2001-2002 Greg Kroah-Hartman * Copyright (C) 2001 Networks Associates Technology, Inc * Copyright (C) 2016 Mellanox Technologies + * Copyright (C) 2023 Microsoft Corporation */ #define pr_fmt(fmt) "LSM: " fmt @@ -880,16 +881,61 @@ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) return __vm_enough_memory(mm, pages, cap_sys_admin); } +/** + * security_bprm_creds_for_exec() - Prepare the credentials for exec() + * @bprm: binary program information + * + * If the setup in prepare_exec_creds did not setup @bprm->cred->security + * properly for executing @bprm->file, update the LSM's portion of + * @bprm->cred->security to be what commit_creds needs to install for the new + * program. This hook may also optionally check permissions (e.g. for + * transitions between security domains). The hook must set @bprm->secureexec + * to 1 if AT_SECURE should be set to request libc enable secure mode. @bprm + * contains the linux_binprm structure. + * + * Return: Returns 0 if the hook is successful and permission is granted. + */ int security_bprm_creds_for_exec(struct linux_binprm *bprm) { return call_int_hook(bprm_creds_for_exec, 0, bprm); } +/** + * security_bprm_creds_from_file() - Update linux_binprm creds based on file + * @bprm: binary program information + * @file: associated file + * + * If @file is setpcap, suid, sgid or otherwise marked to change privilege upon + * exec, update @bprm->cred to reflect that change. This is called after + * finding the binary that will be executed without an interpreter. This + * ensures that the credentials will not be derived from a script that the + * binary will need to reopen, which when reopend may end up being a completely + * different file. This hook may also optionally check permissions (e.g. for + * transitions between security domains). The hook must set @bprm->secureexec + * to 1 if AT_SECURE should be set to request libc enable secure mode. The + * hook must add to @bprm->per_clear any personality flags that should be + * cleared from current->personality. @bprm contains the linux_binprm + * structure. + * + * Return: Returns 0 if the hook is successful and permission is granted. + */ int security_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file) { return call_int_hook(bprm_creds_from_file, 0, bprm, file); } +/** + * security_bprm_check() - Mediate binary handler search + * @bprm: binary program information + * + * This hook mediates the point when a search for a binary handler will begin. + * It allows a check against the @bprm->cred->security value which was set in + * the preceding creds_for_exec call. The argv list and envp list are reliably + * available in @bprm. This hook may be called multiple times during a single + * execve. @bprm contains the linux_binprm structure. + * + * Return: Returns 0 if the hook is successful and permission is granted. + */ int security_bprm_check(struct linux_binprm *bprm) { int ret; @@ -900,11 +946,34 @@ int security_bprm_check(struct linux_binprm *bprm) return ima_bprm_check(bprm); } +/** + * security_bprm_committing_creds() - Install creds for a process during exec() + * @bprm: binary program information + * + * Prepare to install the new security attributes of a process being + * transformed by an execve operation, based on the old credentials pointed to + * by @current->cred and the information set in @bprm->cred by the + * bprm_creds_for_exec hook. @bprm points to the linux_binprm structure. This + * hook is a good place to perform state changes on the process such as closing + * open file descriptors to which access will no longer be granted when the + * attributes are changed. This is called immediately before commit_creds(). + */ void security_bprm_committing_creds(struct linux_binprm *bprm) { call_void_hook(bprm_committing_creds, bprm); } +/** + * security_bprm_committed_creds() - Tidy up after cred install during exec() + * @bprm: binary program information + * + * Tidy up after the installation of the new security attributes of a process + * being transformed by an execve operation. The new credentials have, by this + * point, been set to @current->cred. @bprm points to the linux_binprm + * structure. This hook is a good place to perform state changes on the + * process such as clearing out non-inheritable signal state. This is called + * immediately after commit_creds(). + */ void security_bprm_committed_creds(struct linux_binprm *bprm) { call_void_hook(bprm_committed_creds, bprm); From 36819f185590c1e0e47d095f04bf5da20650fe4d Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 7 Feb 2023 17:33:31 -0500 Subject: [PATCH 02/32] lsm: move the fs_context hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 17 ----------------- security/security.c | 23 +++++++++++++++++++++++ 2 files changed, 23 insertions(+), 17 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 784e19fd665b..a37f3a380918 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,23 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for mount using fs_context. - * [See also Documentation/filesystems/mount_api.rst] - * - * @fs_context_dup: - * Allocate and attach a security structure to sc->security. This pointer - * is initialised to NULL by the caller. - * @fc indicates the new filesystem context. - * @src_fc indicates the original filesystem context. - * Return 0 on success or a negative error code on failure. - * @fs_context_parse_param: - * Userspace provided a parameter to configure a superblock. The LSM may - * reject it with an error and may use it for itself, in which case it - * should return 0; otherwise it should return -ENOPARAM to pass it on to - * the filesystem. - * @fc indicates the filesystem context. - * @param The parameter. - * * Security hooks for filesystem operations. * * @sb_alloc_security: diff --git a/security/security.c b/security/security.c index 1e7dbaf9ad28..64c8805570b1 100644 --- a/security/security.c +++ b/security/security.c @@ -979,11 +979,34 @@ void security_bprm_committed_creds(struct linux_binprm *bprm) call_void_hook(bprm_committed_creds, bprm); } +/** + * security_fs_context_dup() - Duplicate a fs_context LSM blob + * @fc: destination filesystem context + * @src_fc: source filesystem context + * + * Allocate and attach a security structure to sc->security. This pointer is + * initialised to NULL by the caller. @fc indicates the new filesystem context. + * @src_fc indicates the original filesystem context. + * + * Return: Returns 0 on success or a negative error code on failure. + */ int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc) { return call_int_hook(fs_context_dup, 0, fc, src_fc); } +/** + * security_fs_context_parse_param() - Configure a filesystem context + * @fc: filesystem context + * @param: filesystem parameter + * + * Userspace provided a parameter to configure a superblock. The LSM can + * consume the parameter or return it to the caller for use elsewhere. + * + * Return: If the parameter is used by the LSM it should return 0, if it is + * returned to the caller -ENOPARAM is returned, otherwise a negative + * error code is returned. + */ int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param) { From 08526a902cc4bc57bb160e5b1114e67a56fc9280 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 7 Feb 2023 17:44:01 -0500 Subject: [PATCH 03/32] lsm: move the filesystem hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 106 ---------------------- security/security.c | 181 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 181 insertions(+), 106 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index a37f3a380918..3cd6e7abe0df 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,112 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for filesystem operations. - * - * @sb_alloc_security: - * Allocate and attach a security structure to the sb->s_security field. - * The s_security field is initialized to NULL when the structure is - * allocated. - * @sb contains the super_block structure to be modified. - * Return 0 if operation was successful. - * @sb_delete: - * Release objects tied to a superblock (e.g. inodes). - * @sb contains the super_block structure being released. - * @sb_free_security: - * Deallocate and clear the sb->s_security field. - * @sb contains the super_block structure to be modified. - * @sb_free_mnt_opts: - * Free memory associated with @mnt_ops. - * @sb_eat_lsm_opts: - * Eat (scan @orig options) and save them in @mnt_opts. - * Return 0 on success, negative values on failure. - * @sb_statfs: - * Check permission before obtaining filesystem statistics for the @mnt - * mountpoint. - * @dentry is a handle on the superblock for the filesystem. - * Return 0 if permission is granted. - * @sb_mount: - * Check permission before an object specified by @dev_name is mounted on - * the mount point named by @nd. For an ordinary mount, @dev_name - * identifies a device if the file system type requires a device. For a - * remount (@flags & MS_REMOUNT), @dev_name is irrelevant. For a - * loopback/bind mount (@flags & MS_BIND), @dev_name identifies the - * pathname of the object being mounted. - * @dev_name contains the name for object being mounted. - * @path contains the path for mount point object. - * @type contains the filesystem type. - * @flags contains the mount flags. - * @data contains the filesystem-specific data. - * Return 0 if permission is granted. - * @sb_mnt_opts_compat: - * Determine if the new mount options in @mnt_opts are allowed given - * the existing mounted filesystem at @sb. - * @sb superblock being compared. - * @mnt_opts new mount options. - * Return 0 if options are compatible. - * @sb_remount: - * Extracts security system specific mount options and verifies no changes - * are being made to those options. - * @sb superblock being remounted. - * @data contains the filesystem-specific data. - * Return 0 if permission is granted. - * @sb_kern_mount: - * Mount this @sb if allowed by permissions. - * Return 0 if permission is granted. - * @sb_show_options: - * Show (print on @m) mount options for this @sb. - * Return 0 on success, negative values on failure. - * @sb_umount: - * Check permission before the @mnt file system is unmounted. - * @mnt contains the mounted file system. - * @flags contains the unmount flags, e.g. MNT_FORCE. - * Return 0 if permission is granted. - * @sb_pivotroot: - * Check permission before pivoting the root filesystem. - * @old_path contains the path for the new location of the - * current root (put_old). - * @new_path contains the path for the new root (new_root). - * Return 0 if permission is granted. - * @sb_set_mnt_opts: - * Set the security relevant mount options used for a superblock - * @sb the superblock to set security mount options for. - * @opts binary data structure containing all lsm mount data. - * Return 0 on success, error on failure. - * @sb_clone_mnt_opts: - * Copy all security options from a given superblock to another - * @oldsb old superblock which contain information to clone. - * @newsb new superblock which needs filled in. - * Return 0 on success, error on failure. - * @move_mount: - * Check permission before a mount is moved. - * @from_path indicates the mount that is going to be moved. - * @to_path indicates the mountpoint that will be mounted upon. - * Return 0 if permission is granted. - * @dentry_init_security: - * Compute a context for a dentry as the inode is not yet available - * since NFSv4 has no label backed by an EA anyway. - * @dentry dentry to use in calculating the context. - * @mode mode used to determine resource type. - * @name name of the last path component used to create file. - * @xattr_name pointer to place the pointer to security xattr name. - * Caller does not have to free the resulting pointer. Its - * a pointer to static string. - * @ctx pointer to place the pointer to the resulting context in. - * @ctxlen point to place the length of the resulting context. - * Return 0 on success, negative values on failure. - * @dentry_create_files_as: - * Compute a context for a dentry as the inode is not yet available - * and set that context in passed in creds so that new files are - * created using that context. Context is calculated using the - * passed in creds and not the creds of the caller. - * @dentry dentry to use in calculating the context. - * @mode mode used to determine resource type. - * @name name of the last path component used to create file. - * @old creds which should be used for context calculation. - * @new creds to modify. - * Return 0 on success, error on failure. - * - * * Security hooks for inode operations. * * @inode_alloc_security: diff --git a/security/security.c b/security/security.c index 64c8805570b1..f1ab64f390bf 100644 --- a/security/security.c +++ b/security/security.c @@ -1025,6 +1025,16 @@ int security_fs_context_parse_param(struct fs_context *fc, return rc; } +/** + * security_sb_alloc() - Allocate a super_block LSM blob + * @sb: filesystem superblock + * + * Allocate and attach a security structure to the sb->s_security field. The + * s_security field is initialized to NULL when the structure is allocated. + * @sb contains the super_block structure to be modified. + * + * Return: Returns 0 if operation was successful. + */ int security_sb_alloc(struct super_block *sb) { int rc = lsm_superblock_alloc(sb); @@ -1037,11 +1047,25 @@ int security_sb_alloc(struct super_block *sb) return rc; } +/** + * security_sb_delete() - Release super_block LSM associated objects + * @sb: filesystem superblock + * + * Release objects tied to a superblock (e.g. inodes). @sb contains the + * super_block structure being released. + */ void security_sb_delete(struct super_block *sb) { call_void_hook(sb_delete, sb); } +/** + * security_sb_free() - Free a super_block LSM blob + * @sb: filesystem superblock + * + * Deallocate and clear the sb->s_security field. @sb contains the super_block + * structure to be modified. + */ void security_sb_free(struct super_block *sb) { call_void_hook(sb_free_security, sb); @@ -1049,6 +1073,12 @@ void security_sb_free(struct super_block *sb) sb->s_security = NULL; } +/** + * security_free_mnt_opts() - Free memory associated with mount options + * @mnt_ops: LSM processed mount options + * + * Free memory associated with @mnt_ops. + */ void security_free_mnt_opts(void **mnt_opts) { if (!*mnt_opts) @@ -1058,12 +1088,31 @@ void security_free_mnt_opts(void **mnt_opts) } EXPORT_SYMBOL(security_free_mnt_opts); +/** + * security_sb_eat_lsm_opts() - Consume LSM mount options + * @options: mount options + * @mnt_ops: LSM processed mount options + * + * Eat (scan @options) and save them in @mnt_opts. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_sb_eat_lsm_opts(char *options, void **mnt_opts) { return call_int_hook(sb_eat_lsm_opts, 0, options, mnt_opts); } EXPORT_SYMBOL(security_sb_eat_lsm_opts); +/** + * security_sb_mnt_opts_compat() - Check if new mount options are allowed + * @sb: filesystem superblock + * @mnt_opts: new mount options + * + * Determine if the new mount options in @mnt_opts are allowed given the + * existing mounted filesystem at @sb. @sb superblock being compared. + * + * Return: Returns 0 if options are compatible. + */ int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts) { @@ -1071,6 +1120,16 @@ int security_sb_mnt_opts_compat(struct super_block *sb, } EXPORT_SYMBOL(security_sb_mnt_opts_compat); +/** + * security_sb_remount() - Verify no incompatible mount changes during remount + * @sb: filesystem superblock + * @mnt_opts: (re)mount options + * + * Extracts security system specific mount options and verifies no changes are + * being made to those options. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_remount(struct super_block *sb, void *mnt_opts) { @@ -1078,37 +1137,109 @@ int security_sb_remount(struct super_block *sb, } EXPORT_SYMBOL(security_sb_remount); +/** + * security_sb_kern_mount() - Check if a kernel mount is allowed + * @sb: filesystem superblock + * + * Mount this @sb if allowed by permissions. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_kern_mount(struct super_block *sb) { return call_int_hook(sb_kern_mount, 0, sb); } +/** + * security_sb_show_options() - Output the mount options for a superblock + * @m: output file + * @sb: filesystem superblock + * + * Show (print on @m) mount options for this @sb. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_sb_show_options(struct seq_file *m, struct super_block *sb) { return call_int_hook(sb_show_options, 0, m, sb); } +/** + * security_sb_statfs() - Check if accessing fs stats is allowed + * @dentry: superblock handle + * + * Check permission before obtaining filesystem statistics for the @mnt + * mountpoint. @dentry is a handle on the superblock for the filesystem. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_statfs(struct dentry *dentry) { return call_int_hook(sb_statfs, 0, dentry); } +/** + * security_sb_mount() - Check permission for mounting a filesystem + * @dev_name: filesystem backing device + * @path: mount point + * @type: filesystem type + * @flags: mount flags + * @data: filesystem specific data + * + * Check permission before an object specified by @dev_name is mounted on the + * mount point named by @nd. For an ordinary mount, @dev_name identifies a + * device if the file system type requires a device. For a remount + * (@flags & MS_REMOUNT), @dev_name is irrelevant. For a loopback/bind mount + * (@flags & MS_BIND), @dev_name identifies the pathname of the object being + * mounted. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_mount(const char *dev_name, const struct path *path, const char *type, unsigned long flags, void *data) { return call_int_hook(sb_mount, 0, dev_name, path, type, flags, data); } +/** + * security_sb_umount() - Check permission for unmounting a filesystem + * @mnt: mounted filesystem + * @flags: unmount flags + * + * Check permission before the @mnt file system is unmounted. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_umount(struct vfsmount *mnt, int flags) { return call_int_hook(sb_umount, 0, mnt, flags); } +/** + * security_sb_pivotroot() - Check permissions for pivoting the rootfs + * @old_path: new location for current rootfs + * @new_path: location of the new rootfs + * + * Check permission before pivoting the root filesystem. + * + * Return: Returns 0 if permission is granted. + */ int security_sb_pivotroot(const struct path *old_path, const struct path *new_path) { return call_int_hook(sb_pivotroot, 0, old_path, new_path); } +/** + * security_sb_set_mnt_opts() - Set the mount options for a filesystem + * @sb: filesystem superblock + * @mnt_opts: binary mount options + * @kern_flags: kernel flags (in) + * @set_kern_flags: kernel flags (out) + * + * Set the security relevant mount options used for a superblock. + * + * Return: Returns 0 on success, error on failure. + */ int security_sb_set_mnt_opts(struct super_block *sb, void *mnt_opts, unsigned long kern_flags, @@ -1120,6 +1251,17 @@ int security_sb_set_mnt_opts(struct super_block *sb, } EXPORT_SYMBOL(security_sb_set_mnt_opts); +/** + * security_sb_clone_mnt_opts() - Duplicate superblock mount options + * @olddb: source superblock + * @newdb: destination superblock + * @kern_flags: kernel flags (in) + * @set_kern_flags: kernel flags (out) + * + * Copy all security options from a given superblock to another. + * + * Return: Returns 0 on success, error on failure. + */ int security_sb_clone_mnt_opts(const struct super_block *oldsb, struct super_block *newsb, unsigned long kern_flags, @@ -1130,6 +1272,15 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb, } EXPORT_SYMBOL(security_sb_clone_mnt_opts); +/** + * security_move_mount() - Check permissions for moving a mount + * @from_path: source mount point + * @to_path: destination mount point + * + * Check permission before a mount is moved. + * + * Return: Returns 0 if permission is granted. + */ int security_move_mount(const struct path *from_path, const struct path *to_path) { return call_int_hook(move_mount, 0, from_path, to_path); @@ -1179,6 +1330,21 @@ void security_inode_free(struct inode *inode) inode_free_by_rcu); } +/** + * security_dentry_init_security() - Perform dentry initialization + * @dentry: the dentry to initialize + * @mode: mode used to determine resource type + * @name: name of the last path component + * @xattr_name: name of the security/LSM xattr + * @ctx: pointer to the resulting LSM context + * @ctxlen: length of @ctx + * + * Compute a context for a dentry as the inode is not yet available since NFSv4 + * has no label backed by an EA anyway. It is important to note that + * @xattr_name does not need to be free'd by the caller, it is a static string. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_dentry_init_security(struct dentry *dentry, int mode, const struct qstr *name, const char **xattr_name, void **ctx, @@ -1200,6 +1366,21 @@ int security_dentry_init_security(struct dentry *dentry, int mode, } EXPORT_SYMBOL(security_dentry_init_security); +/** + * security_dentry_create_files_as() - Perform dentry initialization + * @dentry: the dentry to initialize + * @mode: mode used to determine resource type + * @name: name of the last path component + * @old: creds to use for LSM context calculations + * @new: creds to modify + * + * Compute a context for a dentry as the inode is not yet available and set + * that context in passed in creds so that new files are created using that + * context. Context is calculated using the passed in creds and not the creds + * of the caller. + * + * Return: Returns 0 on success, error on failure. + */ int security_dentry_create_files_as(struct dentry *dentry, int mode, struct qstr *name, const struct cred *old, struct cred *new) From 916e32584dfaff068792db70c89936801b476ad0 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 8 Feb 2023 16:31:55 -0500 Subject: [PATCH 04/32] lsm: move the inode hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 303 ---------------------- security/security.c | 524 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 524 insertions(+), 303 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 3cd6e7abe0df..3cdd58424796 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,309 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for inode operations. - * - * @inode_alloc_security: - * Allocate and attach a security structure to @inode->i_security. The - * i_security field is initialized to NULL when the inode structure is - * allocated. - * @inode contains the inode structure. - * Return 0 if operation was successful. - * @inode_free_security: - * @inode contains the inode structure. - * Deallocate the inode security structure and set @inode->i_security to - * NULL. - * @inode_init_security: - * Obtain the security attribute name suffix and value to set on a newly - * created inode and set up the incore security field for the new inode. - * This hook is called by the fs code as part of the inode creation - * transaction and provides for atomic labeling of the inode, unlike - * the post_create/mkdir/... hooks called by the VFS. The hook function - * is expected to allocate the name and value via kmalloc, with the caller - * being responsible for calling kfree after using them. - * If the security module does not use security attributes or does - * not wish to put a security attribute on this particular inode, - * then it should return -EOPNOTSUPP to skip this processing. - * @inode contains the inode structure of the newly created inode. - * @dir contains the inode structure of the parent directory. - * @qstr contains the last path component of the new object. - * @name will be set to the allocated name suffix (e.g. selinux). - * @value will be set to the allocated attribute value. - * @len will be set to the length of the value. - * Returns 0 if @name and @value have been successfully set, - * -EOPNOTSUPP if no security attribute is needed, or - * -ENOMEM on memory allocation failure. - * @inode_init_security_anon: - * Set up the incore security field for the new anonymous inode - * and return whether the inode creation is permitted by the security - * module or not. - * @inode contains the inode structure. - * @name name of the anonymous inode class. - * @context_inode optional related inode. - * Returns 0 on success, -EACCES if the security module denies the - * creation of this inode, or another -errno upon other errors. - * @inode_create: - * Check permission to create a regular file. - * @dir contains inode structure of the parent of the new file. - * @dentry contains the dentry structure for the file to be created. - * @mode contains the file mode of the file to be created. - * Return 0 if permission is granted. - * @inode_link: - * Check permission before creating a new hard link to a file. - * @old_dentry contains the dentry structure for an existing - * link to the file. - * @dir contains the inode structure of the parent directory - * of the new link. - * @new_dentry contains the dentry structure for the new link. - * Return 0 if permission is granted. - * @path_link: - * Check permission before creating a new hard link to a file. - * @old_dentry contains the dentry structure for an existing link - * to the file. - * @new_dir contains the path structure of the parent directory of - * the new link. - * @new_dentry contains the dentry structure for the new link. - * Return 0 if permission is granted. - * @inode_unlink: - * Check the permission to remove a hard link to a file. - * @dir contains the inode structure of parent directory of the file. - * @dentry contains the dentry structure for file to be unlinked. - * Return 0 if permission is granted. - * @path_unlink: - * Check the permission to remove a hard link to a file. - * @dir contains the path structure of parent directory of the file. - * @dentry contains the dentry structure for file to be unlinked. - * Return 0 if permission is granted. - * @inode_symlink: - * Check the permission to create a symbolic link to a file. - * @dir contains the inode structure of parent directory of - * the symbolic link. - * @dentry contains the dentry structure of the symbolic link. - * @old_name contains the pathname of file. - * Return 0 if permission is granted. - * @path_symlink: - * Check the permission to create a symbolic link to a file. - * @dir contains the path structure of parent directory of - * the symbolic link. - * @dentry contains the dentry structure of the symbolic link. - * @old_name contains the pathname of file. - * Return 0 if permission is granted. - * @inode_mkdir: - * Check permissions to create a new directory in the existing directory - * associated with inode structure @dir. - * @dir contains the inode structure of parent of the directory - * to be created. - * @dentry contains the dentry structure of new directory. - * @mode contains the mode of new directory. - * Return 0 if permission is granted. - * @path_mkdir: - * Check permissions to create a new directory in the existing directory - * associated with path structure @path. - * @dir contains the path structure of parent of the directory - * to be created. - * @dentry contains the dentry structure of new directory. - * @mode contains the mode of new directory. - * Return 0 if permission is granted. - * @inode_rmdir: - * Check the permission to remove a directory. - * @dir contains the inode structure of parent of the directory - * to be removed. - * @dentry contains the dentry structure of directory to be removed. - * Return 0 if permission is granted. - * @path_rmdir: - * Check the permission to remove a directory. - * @dir contains the path structure of parent of the directory to be - * removed. - * @dentry contains the dentry structure of directory to be removed. - * Return 0 if permission is granted. - * @inode_mknod: - * Check permissions when creating a special file (or a socket or a fifo - * file created via the mknod system call). Note that if mknod operation - * is being done for a regular file, then the create hook will be called - * and not this hook. - * @dir contains the inode structure of parent of the new file. - * @dentry contains the dentry structure of the new file. - * @mode contains the mode of the new file. - * @dev contains the device number. - * Return 0 if permission is granted. - * @path_mknod: - * Check permissions when creating a file. Note that this hook is called - * even if mknod operation is being done for a regular file. - * @dir contains the path structure of parent of the new file. - * @dentry contains the dentry structure of the new file. - * @mode contains the mode of the new file. - * @dev contains the undecoded device number. Use new_decode_dev() to get - * the decoded device number. - * Return 0 if permission is granted. - * @inode_rename: - * Check for permission to rename a file or directory. - * @old_dir contains the inode structure for parent of the old link. - * @old_dentry contains the dentry structure of the old link. - * @new_dir contains the inode structure for parent of the new link. - * @new_dentry contains the dentry structure of the new link. - * Return 0 if permission is granted. - * @path_rename: - * Check for permission to rename a file or directory. - * @old_dir contains the path structure for parent of the old link. - * @old_dentry contains the dentry structure of the old link. - * @new_dir contains the path structure for parent of the new link. - * @new_dentry contains the dentry structure of the new link. - * @flags may contain rename options such as RENAME_EXCHANGE. - * Return 0 if permission is granted. - * @path_chmod: - * Check for permission to change a mode of the file @path. The new - * mode is specified in @mode. - * @path contains the path structure of the file to change the mode. - * @mode contains the new DAC's permission, which is a bitmask of - * constants from . - * Return 0 if permission is granted. - * @path_chown: - * Check for permission to change owner/group of a file or directory. - * @path contains the path structure. - * @uid contains new owner's ID. - * @gid contains new group's ID. - * Return 0 if permission is granted. - * @path_chroot: - * Check for permission to change root directory. - * @path contains the path structure. - * Return 0 if permission is granted. - * @path_notify: - * Check permissions before setting a watch on events as defined by @mask, - * on an object at @path, whose type is defined by @obj_type. - * Return 0 if permission is granted. - * @inode_readlink: - * Check the permission to read the symbolic link. - * @dentry contains the dentry structure for the file link. - * Return 0 if permission is granted. - * @inode_follow_link: - * Check permission to follow a symbolic link when looking up a pathname. - * @dentry contains the dentry structure for the link. - * @inode contains the inode, which itself is not stable in RCU-walk. - * @rcu indicates whether we are in RCU-walk mode. - * Return 0 if permission is granted. - * @inode_permission: - * Check permission before accessing an inode. This hook is called by the - * existing Linux permission function, so a security module can use it to - * provide additional checking for existing Linux permission checks. - * Notice that this hook is called when a file is opened (as well as many - * other operations), whereas the file_security_ops permission hook is - * called when the actual read/write operations are performed. - * @inode contains the inode structure to check. - * @mask contains the permission mask. - * Return 0 if permission is granted. - * @inode_setattr: - * Check permission before setting file attributes. Note that the kernel - * call to notify_change is performed from several locations, whenever - * file attributes change (such as when a file is truncated, chown/chmod - * operations, transferring disk quotas, etc). - * @dentry contains the dentry structure for the file. - * @attr is the iattr structure containing the new file attributes. - * Return 0 if permission is granted. - * @path_truncate: - * Check permission before truncating the file indicated by path. - * Note that truncation permissions may also be checked based on - * already opened files, using the @file_truncate hook. - * @path contains the path structure for the file. - * Return 0 if permission is granted. - * @inode_getattr: - * Check permission before obtaining file attributes. - * @path contains the path structure for the file. - * Return 0 if permission is granted. - * @inode_setxattr: - * Check permission before setting the extended attributes - * @value identified by @name for @dentry. - * Return 0 if permission is granted. - * @inode_post_setxattr: - * Update inode security field after successful setxattr operation. - * @value identified by @name for @dentry. - * @inode_getxattr: - * Check permission before obtaining the extended attributes - * identified by @name for @dentry. - * Return 0 if permission is granted. - * @inode_listxattr: - * Check permission before obtaining the list of extended attribute - * names for @dentry. - * Return 0 if permission is granted. - * @inode_removexattr: - * Check permission before removing the extended attribute - * identified by @name for @dentry. - * Return 0 if permission is granted. - * @inode_set_acl: - * Check permission before setting posix acls - * The posix acls in @kacl are identified by @acl_name. - * Return 0 if permission is granted. - * @inode_get_acl: - * Check permission before getting osix acls - * The posix acls are identified by @acl_name. - * Return 0 if permission is granted. - * @inode_remove_acl: - * Check permission before removing posix acls - * The posix acls are identified by @acl_name. - * Return 0 if permission is granted. - * @inode_getsecurity: - * Retrieve a copy of the extended attribute representation of the - * security label associated with @name for @inode via @buffer. Note that - * @name is the remainder of the attribute name after the security prefix - * has been removed. @alloc is used to specify if the call should return a - * value via the buffer or just the value length. - * Return size of buffer on success. - * @inode_setsecurity: - * Set the security label associated with @name for @inode from the - * extended attribute value @value. @size indicates the size of the - * @value in bytes. @flags may be XATTR_CREATE, XATTR_REPLACE, or 0. - * Note that @name is the remainder of the attribute name after the - * security. prefix has been removed. - * Return 0 on success. - * @inode_listsecurity: - * Copy the extended attribute names for the security labels - * associated with @inode into @buffer. The maximum size of @buffer - * is specified by @buffer_size. @buffer may be NULL to request - * the size of the buffer required. - * Returns number of bytes used/required on success. - * @inode_need_killpriv: - * Called when an inode has been changed. - * @dentry is the dentry being changed. - * Return <0 on error to abort the inode change operation. - * Return 0 if inode_killpriv does not need to be called. - * Return >0 if inode_killpriv does need to be called. - * @inode_killpriv: - * The setuid bit is being removed. Remove similar security labels. - * Called with the dentry->d_inode->i_mutex held. - * @idmap: idmap of the mount. - * @dentry is the dentry being changed. - * Return 0 on success. If error is returned, then the operation - * causing setuid bit removal is failed. - * @inode_getsecid: - * Get the secid associated with the node. - * @inode contains a pointer to the inode. - * @secid contains a pointer to the location where result will be saved. - * In case of failure, @secid will be set to zero. - * @inode_copy_up: - * A file is about to be copied up from lower layer to upper layer of - * overlay filesystem. Security module can prepare a set of new creds - * and modify as need be and return new creds. Caller will switch to - * new creds temporarily to create new file and release newly allocated - * creds. - * @src indicates the union dentry of file that is being copied up. - * @new pointer to pointer to return newly allocated creds. - * Returns 0 on success or a negative error code on error. - * @inode_copy_up_xattr: - * Filter the xattrs being copied up when a unioned file is copied - * up from a lower layer to the union/overlay layer. - * @name indicates the name of the xattr. - * Returns 0 to accept the xattr, 1 to discard the xattr, -EOPNOTSUPP if - * security module does not know about attribute or a negative error code - * to abort the copy up. Note that the caller is responsible for reading - * and writing the xattrs as this hook is merely a filter. - * @d_instantiate: - * Fill in @inode security information for a @dentry if allowed. - * @getprocattr: - * Read attribute @name for process @p and store it into @value if allowed. - * Return the length of @value on success, a negative value otherwise. - * @setprocattr: - * Write (set) attribute @name to @value, size @size if allowed. - * Return written bytes on success, a negative value otherwise. - * * Security hooks for kernfs node operations * * @kernfs_init_security: diff --git a/security/security.c b/security/security.c index f1ab64f390bf..bd35854f956a 100644 --- a/security/security.c +++ b/security/security.c @@ -1286,12 +1286,33 @@ int security_move_mount(const struct path *from_path, const struct path *to_path return call_int_hook(move_mount, 0, from_path, to_path); } +/** + * security_path_notify() - Check if setting a watch is allowed + * @path: file path + * @mask: event mask + * @obj_type: file path type + * + * Check permissions before setting a watch on events as defined by @mask, on + * an object at @path, whose type is defined by @obj_type. + * + * Return: Returns 0 if permission is granted. + */ int security_path_notify(const struct path *path, u64 mask, unsigned int obj_type) { return call_int_hook(path_notify, 0, path, mask, obj_type); } +/** + * security_inode_alloc() - Allocate an inode LSM blob + * @inode: the inode + * + * Allocate and attach a security structure to @inode->i_security. The + * i_security field is initialized to NULL when the inode structure is + * allocated. + * + * Return: Return 0 if operation was successful. + */ int security_inode_alloc(struct inode *inode) { int rc = lsm_inode_alloc(inode); @@ -1312,6 +1333,12 @@ static void inode_free_by_rcu(struct rcu_head *head) kmem_cache_free(lsm_inode_cache, head); } +/** + * security_inode_free() - Free an inode's LSM blob + * @inode: the inode + * + * Deallocate the inode security structure and set @inode->i_security to NULL. + */ void security_inode_free(struct inode *inode) { integrity_inode_free(inode); @@ -1390,6 +1417,27 @@ int security_dentry_create_files_as(struct dentry *dentry, int mode, } EXPORT_SYMBOL(security_dentry_create_files_as); +/** + * security_inode_init_security() - Initialize an inode's LSM context + * @inode: the inode + * @dir: parent directory + * @qstr: last component of the pathname + * @initxattrs: callback function to write xattrs + * @fs_data: filesystem specific data + * + * Obtain the security attribute name suffix and value to set on a newly + * created inode and set up the incore security field for the new inode. This + * hook is called by the fs code as part of the inode creation transaction and + * provides for atomic labeling of the inode, unlike the post_create/mkdir/... + * hooks called by the VFS. The hook function is expected to allocate the name + * and value via kmalloc, with the caller being responsible for calling kfree + * after using them. If the security module does not use security attributes + * or does not wish to put a security attribute on this particular inode, then + * it should return -EOPNOTSUPP to skip this processing. + * + * Return: Returns 0 on success, -EOPNOTSUPP if no security attribute is + * needed, or -ENOMEM on memory allocation failure. + */ int security_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, const initxattrs initxattrs, void *fs_data) @@ -1425,6 +1473,18 @@ out: } EXPORT_SYMBOL(security_inode_init_security); +/** + * security_inode_init_security_anon() - Initialize an anonymous inode + * @inode: the inode + * @name: the anonymous inode class + * @context_inode: an optional related inode + * + * Set up the incore security field for the new anonymous inode and return + * whether the inode creation is permitted by the security module or not. + * + * Return: Returns 0 on success, -EACCES if the security module denies the + * creation of this inode, or another -errno upon other errors. + */ int security_inode_init_security_anon(struct inode *inode, const struct qstr *name, const struct inode *context_inode) @@ -1445,6 +1505,18 @@ int security_old_inode_init_security(struct inode *inode, struct inode *dir, EXPORT_SYMBOL(security_old_inode_init_security); #ifdef CONFIG_SECURITY_PATH +/** + * security_path_mknod() - Check if creating a special file is allowed + * @dir: parent directory + * @dentry: new file + * @mode: new file mode + * @dev: device number + * + * Check permissions when creating a file. Note that this hook is called even + * if mknod operation is being done for a regular file. + * + * Return: Returns 0 if permission is granted. + */ int security_path_mknod(const struct path *dir, struct dentry *dentry, umode_t mode, unsigned int dev) { @@ -1454,6 +1526,16 @@ int security_path_mknod(const struct path *dir, struct dentry *dentry, umode_t m } EXPORT_SYMBOL(security_path_mknod); +/** + * security_path_mkdir() - Check if creating a new directory is allowed + * @dir: parent directory + * @dentry: new directory + * @mode: new directory mode + * + * Check permissions to create a new directory in the existing directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_mkdir(const struct path *dir, struct dentry *dentry, umode_t mode) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) @@ -1462,6 +1544,15 @@ int security_path_mkdir(const struct path *dir, struct dentry *dentry, umode_t m } EXPORT_SYMBOL(security_path_mkdir); +/** + * security_path_rmdir() - Check if removing a directory is allowed + * @dir: parent directory + * @dentry: directory to remove + * + * Check the permission to remove a directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_rmdir(const struct path *dir, struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) @@ -1469,6 +1560,15 @@ int security_path_rmdir(const struct path *dir, struct dentry *dentry) return call_int_hook(path_rmdir, 0, dir, dentry); } +/** + * security_path_unlink() - Check if removing a hard link is allowed + * @dir: parent directory + * @dentry: file + * + * Check the permission to remove a hard link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_path_unlink(const struct path *dir, struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) @@ -1477,6 +1577,16 @@ int security_path_unlink(const struct path *dir, struct dentry *dentry) } EXPORT_SYMBOL(security_path_unlink); +/** + * security_path_symlink() - Check if creating a symbolic link is allowed + * @dir: parent directory + * @dentry: symbolic link + * @old_name: file pathname + * + * Check the permission to create a symbolic link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_path_symlink(const struct path *dir, struct dentry *dentry, const char *old_name) { @@ -1485,6 +1595,16 @@ int security_path_symlink(const struct path *dir, struct dentry *dentry, return call_int_hook(path_symlink, 0, dir, dentry, old_name); } +/** + * security_path_link - Check if creating a hard link is allowed + * @old_dentry: existing file + * @new_dir: new parent directory + * @new_dentry: new link + * + * Check permission before creating a new hard link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_path_link(struct dentry *old_dentry, const struct path *new_dir, struct dentry *new_dentry) { @@ -1493,6 +1613,18 @@ int security_path_link(struct dentry *old_dentry, const struct path *new_dir, return call_int_hook(path_link, 0, old_dentry, new_dir, new_dentry); } +/** + * security_path_rename() - Check if renaming a file is allowed + * @old_dir: parent directory of the old file + * @old_dentry: the old file + * @new_dir: parent directory of the new file + * @new_dentry: the new file + * @flags: flags + * + * Check for permission to rename a file or directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_rename(const struct path *old_dir, struct dentry *old_dentry, const struct path *new_dir, struct dentry *new_dentry, unsigned int flags) @@ -1506,6 +1638,16 @@ int security_path_rename(const struct path *old_dir, struct dentry *old_dentry, } EXPORT_SYMBOL(security_path_rename); +/** + * security_path_truncate() - Check if truncating a file is allowed + * @path: file + * + * Check permission before truncating the file indicated by path. Note that + * truncation permissions may also be checked based on already opened files, + * using the security_file_truncate() hook. + * + * Return: Returns 0 if permission is granted. + */ int security_path_truncate(const struct path *path) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) @@ -1513,6 +1655,17 @@ int security_path_truncate(const struct path *path) return call_int_hook(path_truncate, 0, path); } +/** + * security_path_chmod() - Check if changing the file's mode is allowed + * @path: file + * @mode: new mode + * + * Check for permission to change a mode of the file @path. The new mode is + * specified in @mode which is a bitmask of constants from + * . + * + * Return: Returns 0 if permission is granted. + */ int security_path_chmod(const struct path *path, umode_t mode) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) @@ -1520,6 +1673,16 @@ int security_path_chmod(const struct path *path, umode_t mode) return call_int_hook(path_chmod, 0, path, mode); } +/** + * security_path_chown() - Check if changing the file's owner/group is allowed + * @path: file + * @uid: file owner + * @gid: file group + * + * Check for permission to change owner/group of a file or directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_chown(const struct path *path, kuid_t uid, kgid_t gid) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) @@ -1527,12 +1690,30 @@ int security_path_chown(const struct path *path, kuid_t uid, kgid_t gid) return call_int_hook(path_chown, 0, path, uid, gid); } +/** + * security_path_chroot() - Check if changing the root directory is allowed + * @path: directory + * + * Check for permission to change root directory. + * + * Return: Returns 0 if permission is granted. + */ int security_path_chroot(const struct path *path) { return call_int_hook(path_chroot, 0, path); } #endif +/** + * security_inode_create() - Check if creating a file is allowed + * @dir: the parent directory + * @dentry: the file being created + * @mode: requested file mode + * + * Check permission to create a regular file. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) { if (unlikely(IS_PRIVATE(dir))) @@ -1541,6 +1722,16 @@ int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode } EXPORT_SYMBOL_GPL(security_inode_create); +/** + * security_inode_link() - Check if creating a hard link is allowed + * @old_dentry: existing file + * @dir: new parent directory + * @new_dentry: new link + * + * Check permission before creating a new hard link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) { @@ -1549,6 +1740,15 @@ int security_inode_link(struct dentry *old_dentry, struct inode *dir, return call_int_hook(inode_link, 0, old_dentry, dir, new_dentry); } +/** + * security_inode_unlink() - Check if removing a hard link is allowed + * @dir: parent directory + * @dentry: file + * + * Check the permission to remove a hard link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_unlink(struct inode *dir, struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) @@ -1556,6 +1756,16 @@ int security_inode_unlink(struct inode *dir, struct dentry *dentry) return call_int_hook(inode_unlink, 0, dir, dentry); } +/** + * security_inode_symlink() Check if creating a symbolic link is allowed + * @dir: parent directory + * @dentry: symbolic link + * @old_name: existing filename + * + * Check the permission to create a symbolic link to a file. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_symlink(struct inode *dir, struct dentry *dentry, const char *old_name) { @@ -1564,6 +1774,17 @@ int security_inode_symlink(struct inode *dir, struct dentry *dentry, return call_int_hook(inode_symlink, 0, dir, dentry, old_name); } +/** + * security_inode_mkdir() - Check if creation a new director is allowed + * @dir: parent directory + * @dentry: new directory + * @mode: new directory mode + * + * Check permissions to create a new directory in the existing directory + * associated with inode structure @dir. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { if (unlikely(IS_PRIVATE(dir))) @@ -1572,6 +1793,15 @@ int security_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) } EXPORT_SYMBOL_GPL(security_inode_mkdir); +/** + * security_inode_rmdir() - Check if removing a directory is allowed + * @dir: parent directory + * @dentry: directory to be removed + * + * Check the permission to remove a directory. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_rmdir(struct inode *dir, struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) @@ -1579,6 +1809,20 @@ int security_inode_rmdir(struct inode *dir, struct dentry *dentry) return call_int_hook(inode_rmdir, 0, dir, dentry); } +/** + * security_inode_mknod() - Check if creating a special file is allowed + * @dir: parent directory + * @dentry: new file + * @mode: new file mode + * @dev: device number + * + * Check permissions when creating a special file (or a socket or a fifo file + * created via the mknod system call). Note that if mknod operation is being + * done for a regular file, then the create hook will be called and not this + * hook. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { if (unlikely(IS_PRIVATE(dir))) @@ -1586,6 +1830,18 @@ int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, return call_int_hook(inode_mknod, 0, dir, dentry, mode, dev); } +/** + * security_inode_rename() - Check if renaming a file is allowed + * @old_dir: parent directory of the old file + * @old_dentry: the old file + * @new_dir: parent directory of the new file + * @new_dentry: the new file + * @flags: flags + * + * Check for permission to rename a file or directory. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) @@ -1605,6 +1861,14 @@ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry, new_dir, new_dentry); } +/** + * security_inode_readlink() - Check if reading a symbolic link is allowed + * @dentry: link + * + * Check the permission to read the symbolic link. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_readlink(struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) @@ -1612,6 +1876,17 @@ int security_inode_readlink(struct dentry *dentry) return call_int_hook(inode_readlink, 0, dentry); } +/** + * security_inode_follow_link() - Check if following a symbolic link is allowed + * @dentry: link dentry + * @inode: link inode + * @rcu: true if in RCU-walk mode + * + * Check permission to follow a symbolic link when looking up a pathname. If + * @rcu is true, @inode is not stable. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_follow_link(struct dentry *dentry, struct inode *inode, bool rcu) { @@ -1620,6 +1895,20 @@ int security_inode_follow_link(struct dentry *dentry, struct inode *inode, return call_int_hook(inode_follow_link, 0, dentry, inode, rcu); } +/** + * security_inode_permission() - Check if accessing an inode is allowed + * @inode: inode + * @mask: access mask + * + * Check permission before accessing an inode. This hook is called by the + * existing Linux permission function, so a security module can use it to + * provide additional checking for existing Linux permission checks. Notice + * that this hook is called when a file is opened (as well as many other + * operations), whereas the file_security_ops permission hook is called when + * the actual read/write operations are performed. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_permission(struct inode *inode, int mask) { if (unlikely(IS_PRIVATE(inode))) @@ -1627,6 +1916,19 @@ int security_inode_permission(struct inode *inode, int mask) return call_int_hook(inode_permission, 0, inode, mask); } +/** + * security_inode_setattr() - Check if setting file attributes is allowed + * @idmap: idmap of the mount + * @dentry: file + * @attr: new attributes + * + * Check permission before setting file attributes. Note that the kernel call + * to notify_change is performed from several locations, whenever file + * attributes change (such as when a file is truncated, chown/chmod operations, + * transferring disk quotas, etc). + * + * Return: Returns 0 if permission is granted. + */ int security_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr) { @@ -1641,6 +1943,14 @@ int security_inode_setattr(struct mnt_idmap *idmap, } EXPORT_SYMBOL_GPL(security_inode_setattr); +/** + * security_inode_getattr() - Check if getting file attributes is allowed + * @path: file + * + * Check permission before obtaining file attributes. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_getattr(const struct path *path) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry)))) @@ -1648,6 +1958,18 @@ int security_inode_getattr(const struct path *path) return call_int_hook(inode_getattr, 0, path); } +/** + * security_inode_setxattr() - Check if setting file xattrs is allowed + * @idmap: idmap of the mount + * @dentry: file + * @name: xattr name + * @value: xattr value + * @flags: flags + * + * Check permission before setting the extended attributes. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, const char *name, const void *value, size_t size, int flags) @@ -1673,6 +1995,18 @@ int security_inode_setxattr(struct mnt_idmap *idmap, return evm_inode_setxattr(idmap, dentry, name, value, size); } +/** + * security_inode_set_acl() - Check if setting posix acls is allowed + * @idmap: idmap of the mount + * @dentry: file + * @acl_name: acl name + * @kacl: acl struct + * + * Check permission before setting posix acls, the posix acls in @kacl are + * identified by @acl_name. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl) @@ -1691,6 +2025,17 @@ int security_inode_set_acl(struct mnt_idmap *idmap, return evm_inode_set_acl(idmap, dentry, acl_name, kacl); } +/** + * security_inode_get_acl() - Check if reading posix acls is allowed + * @idmap: idmap of the mount + * @dentry: file + * @acl_name: acl name + * + * Check permission before getting osix acls, the posix acls are identified by + * @acl_name. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) { @@ -1699,6 +2044,17 @@ int security_inode_get_acl(struct mnt_idmap *idmap, return call_int_hook(inode_get_acl, 0, idmap, dentry, acl_name); } +/** + * security_inode_remove_acl() - Check if removing a posix acl is allowed + * @idmap: idmap of the mount + * @dentry: file + * @acl_name: acl name + * + * Check permission before removing posix acls, the posix acls are identified + * by @acl_name. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) { @@ -1715,6 +2071,16 @@ int security_inode_remove_acl(struct mnt_idmap *idmap, return evm_inode_remove_acl(idmap, dentry, acl_name); } +/** + * security_inode_post_setxattr() - Update the inode after a setxattr operation + * @dentry: file + * @name: xattr name + * @value: xattr value + * @size: xattr value size + * @flags: flags + * + * Update inode security field after successful setxattr operation. + */ void security_inode_post_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { @@ -1724,6 +2090,16 @@ void security_inode_post_setxattr(struct dentry *dentry, const char *name, evm_inode_post_setxattr(dentry, name, value, size); } +/** + * security_inode_getxattr() - Check if xattr access is allowed + * @dentry: file + * @name: xattr name + * + * Check permission before obtaining the extended attributes identified by + * @name for @dentry. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_getxattr(struct dentry *dentry, const char *name) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) @@ -1731,6 +2107,15 @@ int security_inode_getxattr(struct dentry *dentry, const char *name) return call_int_hook(inode_getxattr, 0, dentry, name); } +/** + * security_inode_listxattr() - Check if listing xattrs is allowed + * @dentry: file + * + * Check permission before obtaining the list of extended attribute names for + * @dentry. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_listxattr(struct dentry *dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) @@ -1738,6 +2123,17 @@ int security_inode_listxattr(struct dentry *dentry) return call_int_hook(inode_listxattr, 0, dentry); } +/** + * security_inode_removexattr() - Check if removing an xattr is allowed + * @idmap: idmap of the mount + * @dentry: file + * @name: xattr name + * + * Check permission before removing the extended attribute identified by @name + * for @dentry. + * + * Return: Returns 0 if permission is granted. + */ int security_inode_removexattr(struct mnt_idmap *idmap, struct dentry *dentry, const char *name) { @@ -1760,17 +2156,55 @@ int security_inode_removexattr(struct mnt_idmap *idmap, return evm_inode_removexattr(idmap, dentry, name); } +/** + * security_inode_need_killpriv() - Check if security_inode_killpriv() required + * @dentry: associated dentry + * + * Called when an inode has been changed to determine if + * security_inode_killpriv() should be called. + * + * Return: Return <0 on error to abort the inode change operation, return 0 if + * security_inode_killpriv() does not need to be called, return >0 if + * security_inode_killpriv() does need to be called. + */ int security_inode_need_killpriv(struct dentry *dentry) { return call_int_hook(inode_need_killpriv, 0, dentry); } +/** + * security_inode_killpriv() - The setuid bit is removed, update LSM state + * @idmap: idmap of the mount + * @dentry: associated dentry + * + * The @dentry's setuid bit is being removed. Remove similar security labels. + * Called with the dentry->d_inode->i_mutex held. + * + * Return: Return 0 on success. If error is returned, then the operation + * causing setuid bit removal is failed. + */ int security_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry) { return call_int_hook(inode_killpriv, 0, idmap, dentry); } +/** + * security_inode_getsecurity() - Get the xattr security label of an inode + * @idmap: idmap of the mount + * @inode: inode + * @name: xattr name + * @buffer: security label buffer + * @alloc: allocation flag + * + * Retrieve a copy of the extended attribute representation of the security + * label associated with @name for @inode via @buffer. Note that @name is the + * remainder of the attribute name after the security prefix has been removed. + * @alloc is used to specify if the call should return a value via the buffer + * or just the value length. + * + * Return: Returns size of buffer on success. + */ int security_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, void **buffer, bool alloc) @@ -1791,6 +2225,21 @@ int security_inode_getsecurity(struct mnt_idmap *idmap, return LSM_RET_DEFAULT(inode_getsecurity); } +/** + * security_inode_setsecurity() - Set the xattr security label of an inode + * @inode: inode + * @name: xattr name + * @value: security label + * @size: length of security label + * @flags: flags + * + * Set the security label associated with @name for @inode from the extended + * attribute value @value. @size indicates the size of the @value in bytes. + * @flags may be XATTR_CREATE, XATTR_REPLACE, or 0. Note that @name is the + * remainder of the attribute name after the security. prefix has been removed. + * + * Return: Returns 0 on success. + */ int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) { struct security_hook_list *hp; @@ -1810,6 +2259,19 @@ int security_inode_setsecurity(struct inode *inode, const char *name, const void return LSM_RET_DEFAULT(inode_setsecurity); } +/** + * security_inode_listsecurity() - List the xattr security label names + * @inode: inode + * @buffer: buffer + * @buffer_size: size of buffer + * + * Copy the extended attribute names for the security labels associated with + * @inode into @buffer. The maximum size of @buffer is specified by + * @buffer_size. @buffer may be NULL to request the size of the buffer + * required. + * + * Return: Returns number of bytes used/required on success. + */ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) { if (unlikely(IS_PRIVATE(inode))) @@ -1818,17 +2280,49 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer } EXPORT_SYMBOL(security_inode_listsecurity); +/** + * security_inode_getsecid() - Get an inode's secid + * @inode: inode + * @secid: secid to return + * + * Get the secid associated with the node. In case of failure, @secid will be + * set to zero. + */ void security_inode_getsecid(struct inode *inode, u32 *secid) { call_void_hook(inode_getsecid, inode, secid); } +/** + * security_inode_copy_up() - Create new creds for an overlayfs copy-up op + * @src: union dentry of copy-up file + * @new: newly created creds + * + * A file is about to be copied up from lower layer to upper layer of overlay + * filesystem. Security module can prepare a set of new creds and modify as + * need be and return new creds. Caller will switch to new creds temporarily to + * create new file and release newly allocated creds. + * + * Return: Returns 0 on success or a negative error code on error. + */ int security_inode_copy_up(struct dentry *src, struct cred **new) { return call_int_hook(inode_copy_up, 0, src, new); } EXPORT_SYMBOL(security_inode_copy_up); +/** + * security_inode_copy_up_xattr() - Filter xattrs in an overlayfs copy-up op + * @name: xattr name + * + * Filter the xattrs being copied up when a unioned file is copied up from a + * lower layer to the union/overlay layer. The caller is responsible for + * reading and writing the xattrs, this hook is merely a filter. + * + * Return: Returns 0 to accept the xattr, 1 to discard the xattr, -EOPNOTSUPP + * if the security module does not know about attribute, or a negative + * error code to abort the copy up. + */ int security_inode_copy_up_xattr(const char *name) { struct security_hook_list *hp; @@ -2405,6 +2899,13 @@ int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops, return call_int_hook(sem_semop, 0, sma, sops, nsops, alter); } +/** + * security_d_instantiate() - Populate an inode's LSM state based on a dentry + * @dentry: dentry + * @inode: inode + * + * Fill in @inode security information for a @dentry if allowed. + */ void security_d_instantiate(struct dentry *dentry, struct inode *inode) { if (unlikely(inode && IS_PRIVATE(inode))) @@ -2413,6 +2914,17 @@ void security_d_instantiate(struct dentry *dentry, struct inode *inode) } EXPORT_SYMBOL(security_d_instantiate); +/** + * security_getprocattr() - Read an attribute for a task + * @p: the task + * @lsm: LSM name + * @name: attribute name + * @value: attribute value + * + * Read attribute @name for task @p and store it into @value if allowed. + * + * Return: Returns the length of @value on success, a negative value otherwise. + */ int security_getprocattr(struct task_struct *p, const char *lsm, const char *name, char **value) { @@ -2426,6 +2938,18 @@ int security_getprocattr(struct task_struct *p, const char *lsm, return LSM_RET_DEFAULT(getprocattr); } +/** + * security_setprocattr() - Set an attribute for a task + * @lsm: LSM name + * @name: attribute name + * @value: attribute value + * @size: attribute value size + * + * Write (set) the current task's attribute @name to @value, size @size if + * allowed. + * + * Return: Returns bytes written on success, a negative value otherwise. + */ int security_setprocattr(const char *lsm, const char *name, void *value, size_t size) { From 9348944b775d9a12ee7ab698df5bad85409bdd48 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Feb 2023 13:20:33 -0500 Subject: [PATCH 05/32] lsm: move the kernfs hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 9 --------- security/security.c | 10 ++++++++++ 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 3cdd58424796..c953f6c356f2 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,15 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for kernfs node operations - * - * @kernfs_init_security: - * Initialize the security context of a newly created kernfs node based - * on its own and its parent's attributes. - * @kn_dir the parent kernfs node. - * @kn the new child kernfs node. - * Return 0 if permission is granted. - * * Security hooks for file operations * * @file_permission: diff --git a/security/security.c b/security/security.c index bd35854f956a..b070a24157ec 100644 --- a/security/security.c +++ b/security/security.c @@ -2344,6 +2344,16 @@ int security_inode_copy_up_xattr(const char *name) } EXPORT_SYMBOL(security_inode_copy_up_xattr); +/** + * security_kernfs_init_security() - Init LSM context for a kernfs node + * @kn_dir: parent kernfs node + * @kn: the kernfs node to initialize + * + * Initialize the security context of a newly created kernfs node based on its + * own and its parent's attributes. + * + * Return: Returns 0 if permission is granted. + */ int security_kernfs_init_security(struct kernfs_node *kn_dir, struct kernfs_node *kn) { From a0fd6480de489780cdf0940a38bb75b949976d6c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 10 Feb 2023 13:23:09 -0500 Subject: [PATCH 06/32] lsm: move the file hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 104 -------------------------- security/security.c | 151 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 151 insertions(+), 104 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index c953f6c356f2..7c58683b9288 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,110 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for file operations - * - * @file_permission: - * Check file permissions before accessing an open file. This hook is - * called by various operations that read or write files. A security - * module can use this hook to perform additional checking on these - * operations, e.g. to revalidate permissions on use to support privilege - * bracketing or policy changes. Notice that this hook is used when the - * actual read/write operations are performed, whereas the - * inode_security_ops hook is called when a file is opened (as well as - * many other operations). - * Caveat: Although this hook can be used to revalidate permissions for - * various system call operations that read or write files, it does not - * address the revalidation of permissions for memory-mapped files. - * Security modules must handle this separately if they need such - * revalidation. - * @file contains the file structure being accessed. - * @mask contains the requested permissions. - * Return 0 if permission is granted. - * @file_alloc_security: - * Allocate and attach a security structure to the file->f_security field. - * The security field is initialized to NULL when the structure is first - * created. - * @file contains the file structure to secure. - * Return 0 if the hook is successful and permission is granted. - * @file_free_security: - * Deallocate and free any security structures stored in file->f_security. - * @file contains the file structure being modified. - * @file_ioctl: - * @file contains the file structure. - * @cmd contains the operation to perform. - * @arg contains the operational arguments. - * Check permission for an ioctl operation on @file. Note that @arg - * sometimes represents a user space pointer; in other cases, it may be a - * simple integer value. When @arg represents a user space pointer, it - * should never be used by the security module. - * Return 0 if permission is granted. - * @mmap_addr: - * Check permissions for a mmap operation at @addr. - * @addr contains virtual address that will be used for the operation. - * Return 0 if permission is granted. - * @mmap_file: - * Check permissions for a mmap operation. The @file may be NULL, e.g. - * if mapping anonymous memory. - * @file contains the file structure for file to map (may be NULL). - * @reqprot contains the protection requested by the application. - * @prot contains the protection that will be applied by the kernel. - * @flags contains the operational flags. - * Return 0 if permission is granted. - * @file_mprotect: - * Check permissions before changing memory access permissions. - * @vma contains the memory region to modify. - * @reqprot contains the protection requested by the application. - * @prot contains the protection that will be applied by the kernel. - * Return 0 if permission is granted. - * @file_lock: - * Check permission before performing file locking operations. - * Note the hook mediates both flock and fcntl style locks. - * @file contains the file structure. - * @cmd contains the posix-translated lock operation to perform - * (e.g. F_RDLCK, F_WRLCK). - * Return 0 if permission is granted. - * @file_fcntl: - * Check permission before allowing the file operation specified by @cmd - * from being performed on the file @file. Note that @arg sometimes - * represents a user space pointer; in other cases, it may be a simple - * integer value. When @arg represents a user space pointer, it should - * never be used by the security module. - * @file contains the file structure. - * @cmd contains the operation to be performed. - * @arg contains the operational arguments. - * Return 0 if permission is granted. - * @file_set_fowner: - * Save owner security information (typically from current->security) in - * file->f_security for later use by the send_sigiotask hook. - * @file contains the file structure to update. - * Return 0 on success. - * @file_send_sigiotask: - * Check permission for the file owner @fown to send SIGIO or SIGURG to the - * process @tsk. Note that this hook is sometimes called from interrupt. - * Note that the fown_struct, @fown, is never outside the context of a - * struct file, so the file structure (and associated security information) - * can always be obtained: container_of(fown, struct file, f_owner) - * @tsk contains the structure of task receiving signal. - * @fown contains the file owner information. - * @sig is the signal that will be sent. When 0, kernel sends SIGIO. - * Return 0 if permission is granted. - * @file_receive: - * This hook allows security modules to control the ability of a process - * to receive an open file descriptor via socket IPC. - * @file contains the file structure being received. - * Return 0 if permission is granted. - * @file_truncate: - * Check permission before truncating a file, i.e. using ftruncate. - * Note that truncation permission may also be checked based on the path, - * using the @path_truncate hook. - * @file contains the file structure for the file. - * Return 0 if permission is granted. - * @file_open: - * Save open-time permission checking state for later use upon - * file_permission, and recheck access if anything has changed - * since inode_permission. - * Return 0 if permission is granted. - * * Security hooks for task operations. * * @task_alloc: diff --git a/security/security.c b/security/security.c index b070a24157ec..a527291c191d 100644 --- a/security/security.c +++ b/security/security.c @@ -2360,6 +2360,25 @@ int security_kernfs_init_security(struct kernfs_node *kn_dir, return call_int_hook(kernfs_init_security, 0, kn_dir, kn); } +/** + * security_file_permission() - Check file permissions + * @file: file + * @mask: requested permissions + * + * Check file permissions before accessing an open file. This hook is called + * by various operations that read or write files. A security module can use + * this hook to perform additional checking on these operations, e.g. to + * revalidate permissions on use to support privilege bracketing or policy + * changes. Notice that this hook is used when the actual read/write + * operations are performed, whereas the inode_security_ops hook is called when + * a file is opened (as well as many other operations). Although this hook can + * be used to revalidate permissions for various system call operations that + * read or write files, it does not address the revalidation of permissions for + * memory-mapped files. Security modules must handle this separately if they + * need such revalidation. + * + * Return: Returns 0 if permission is granted. + */ int security_file_permission(struct file *file, int mask) { int ret; @@ -2371,6 +2390,15 @@ int security_file_permission(struct file *file, int mask) return fsnotify_perm(file, mask); } +/** + * security_file_alloc() - Allocate and init a file's LSM blob + * @file: the file + * + * Allocate and attach a security structure to the file->f_security field. The + * security field is initialized to NULL when the structure is first created. + * + * Return: Return 0 if the hook is successful and permission is granted. + */ int security_file_alloc(struct file *file) { int rc = lsm_file_alloc(file); @@ -2383,6 +2411,12 @@ int security_file_alloc(struct file *file) return rc; } +/** + * security_file_free() - Free a file's LSM blob + * @file: the file + * + * Deallocate and free any security structures stored in file->f_security. + */ void security_file_free(struct file *file) { void *blob; @@ -2396,6 +2430,19 @@ void security_file_free(struct file *file) } } +/** + * security_file_ioctl() - Check if an ioctl is allowed + * @file: associated file + * @cmd: ioctl cmd + * @arg: ioctl arguments + * + * Check permission for an ioctl operation on @file. Note that @arg sometimes + * represents a user space pointer; in other cases, it may be a simple integer + * value. When @arg represents a user space pointer, it should never be used + * by the security module. + * + * Return: Returns 0 if permission is granted. + */ int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { return call_int_hook(file_ioctl, 0, file, cmd, arg); @@ -2435,6 +2482,17 @@ static inline unsigned long mmap_prot(struct file *file, unsigned long prot) return prot; } +/** + * security_mmap_file() - Check if mmap'ing a file is allowed + * @file: file + * @prot: protection applied by the kernel + * @flags: flags + * + * Check permissions for a mmap operation. The @file may be NULL, e.g. if + * mapping anonymous memory. + * + * Return: Returns 0 if permission is granted. + */ int security_mmap_file(struct file *file, unsigned long prot, unsigned long flags) { @@ -2447,11 +2505,29 @@ int security_mmap_file(struct file *file, unsigned long prot, return ima_file_mmap(file, prot, prot_adj, flags); } +/** + * security_mmap_addr() - Check if mmap'ing an address is allowed + * @addr: address + * + * Check permissions for a mmap operation at @addr. + * + * Return: Returns 0 if permission is granted. + */ int security_mmap_addr(unsigned long addr) { return call_int_hook(mmap_addr, 0, addr); } +/** + * security_file_mprotect() - Check if changing memory protections is allowed + * @vma: memory region + * @reqprot: application requested protection + * @prog: protection applied by the kernel + * + * Check permissions before changing memory access permissions. + * + * Return: Returns 0 if permission is granted. + */ int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, unsigned long prot) { @@ -2463,32 +2539,97 @@ int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, return ima_file_mprotect(vma, prot); } +/** + * security_file_lock() - Check if a file lock is allowed + * @file: file + * @cmd: lock operation (e.g. F_RDLCK, F_WRLCK) + * + * Check permission before performing file locking operations. Note the hook + * mediates both flock and fcntl style locks. + * + * Return: Returns 0 if permission is granted. + */ int security_file_lock(struct file *file, unsigned int cmd) { return call_int_hook(file_lock, 0, file, cmd); } +/** + * security_file_fcntl() - Check if fcntl() op is allowed + * @file: file + * @cmd: fnctl command + * @arg: command argument + * + * Check permission before allowing the file operation specified by @cmd from + * being performed on the file @file. Note that @arg sometimes represents a + * user space pointer; in other cases, it may be a simple integer value. When + * @arg represents a user space pointer, it should never be used by the + * security module. + * + * Return: Returns 0 if permission is granted. + */ int security_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg) { return call_int_hook(file_fcntl, 0, file, cmd, arg); } +/** + * security_file_set_fowner() - Set the file owner info in the LSM blob + * @file: the file + * + * Save owner security information (typically from current->security) in + * file->f_security for later use by the send_sigiotask hook. + * + * Return: Returns 0 on success. + */ void security_file_set_fowner(struct file *file) { call_void_hook(file_set_fowner, file); } +/** + * security_file_send_sigiotask() - Check if sending SIGIO/SIGURG is allowed + * @tsk: target task + * @fown: signal sender + * @sig: signal to be sent, SIGIO is sent if 0 + * + * Check permission for the file owner @fown to send SIGIO or SIGURG to the + * process @tsk. Note that this hook is sometimes called from interrupt. Note + * that the fown_struct, @fown, is never outside the context of a struct file, + * so the file structure (and associated security information) can always be + * obtained: container_of(fown, struct file, f_owner). + * + * Return: Returns 0 if permission is granted. + */ int security_file_send_sigiotask(struct task_struct *tsk, struct fown_struct *fown, int sig) { return call_int_hook(file_send_sigiotask, 0, tsk, fown, sig); } +/** + * security_file_receive() - Check is receiving a file via IPC is allowed + * @file: file being received + * + * This hook allows security modules to control the ability of a process to + * receive an open file descriptor via socket IPC. + * + * Return: Returns 0 if permission is granted. + */ int security_file_receive(struct file *file) { return call_int_hook(file_receive, 0, file); } +/** + * security_file_open() - Save open() time state for late use by the LSM + * @file: + * + * Save open-time permission checking state for later use upon file_permission, + * and recheck access if anything has changed since inode_permission. + * + * Return: Returns 0 if permission is granted. + */ int security_file_open(struct file *file) { int ret; @@ -2500,6 +2641,16 @@ int security_file_open(struct file *file) return fsnotify_perm(file, MAY_OPEN); } +/** + * security_file_truncate() - Check if truncating a file is allowed + * @file: file + * + * Check permission before truncating a file, i.e. using ftruncate. Note that + * truncation permission may also be checked based on the path, using the + * @path_truncate hook. + * + * Return: Returns 0 if permission is granted. + */ int security_file_truncate(struct file *file) { return call_int_hook(file_truncate, 0, file); From 130c53bfee4bc70919d356bd8b30137ba4d665b1 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Sat, 11 Feb 2023 19:27:58 -0500 Subject: [PATCH 07/32] lsm: move the task hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 210 ------------------------ security/security.c | 334 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 334 insertions(+), 210 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 7c58683b9288..5578a13729bd 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,216 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for task operations. - * - * @task_alloc: - * @task task being allocated. - * @clone_flags contains the flags indicating what should be shared. - * Handle allocation of task-related resources. - * Returns a zero on success, negative values on failure. - * @task_free: - * @task task about to be freed. - * Handle release of task-related resources. (Note that this can be called - * from interrupt context.) - * @cred_alloc_blank: - * @cred points to the credentials. - * @gfp indicates the atomicity of any memory allocations. - * Only allocate sufficient memory and attach to @cred such that - * cred_transfer() will not get ENOMEM. - * Return 0 on success, negative values on failure. - * @cred_free: - * @cred points to the credentials. - * Deallocate and clear the cred->security field in a set of credentials. - * @cred_prepare: - * @new points to the new credentials. - * @old points to the original credentials. - * @gfp indicates the atomicity of any memory allocations. - * Prepare a new set of credentials by copying the data from the old set. - * Return 0 on success, negative values on failure. - * @cred_transfer: - * @new points to the new credentials. - * @old points to the original credentials. - * Transfer data from original creds to new creds - * @cred_getsecid: - * Retrieve the security identifier of the cred structure @c - * @c contains the credentials, secid will be placed into @secid. - * In case of failure, @secid will be set to zero. - * @kernel_act_as: - * Set the credentials for a kernel service to act as (subjective context). - * @new points to the credentials to be modified. - * @secid specifies the security ID to be set. - * The current task must be the one that nominated @secid. - * Return 0 if successful. - * @kernel_create_files_as: - * Set the file creation context in a set of credentials to be the same as - * the objective context of the specified inode. - * @new points to the credentials to be modified. - * @inode points to the inode to use as a reference. - * The current task must be the one that nominated @inode. - * Return 0 if successful. - * @kernel_module_request: - * Ability to trigger the kernel to automatically upcall to userspace for - * userspace to load a kernel module with the given name. - * @kmod_name name of the module requested by the kernel. - * Return 0 if successful. - * @kernel_load_data: - * Load data provided by userspace. - * @id kernel load data identifier. - * @contents if a subsequent @kernel_post_load_data will be called. - * Return 0 if permission is granted. - * @kernel_post_load_data: - * Load data provided by a non-file source (usually userspace buffer). - * @buf pointer to buffer containing the data contents. - * @size length of the data contents. - * @id kernel load data identifier. - * @description a text description of what was loaded, @id-specific. - * Return 0 if permission is granted. - * This must be paired with a prior @kernel_load_data call that had - * @contents set to true. - * @kernel_read_file: - * Read a file specified by userspace. - * @file contains the file structure pointing to the file being read - * by the kernel. - * @id kernel read file identifier. - * @contents if a subsequent @kernel_post_read_file will be called. - * Return 0 if permission is granted. - * @kernel_post_read_file: - * Read a file specified by userspace. - * @file contains the file structure pointing to the file being read - * by the kernel. - * @buf pointer to buffer containing the file contents. - * @size length of the file contents. - * @id kernel read file identifier. - * This must be paired with a prior @kernel_read_file call that had - * @contents set to true. - * Return 0 if permission is granted. - * @task_fix_setuid: - * Update the module's state after setting one or more of the user - * identity attributes of the current process. The @flags parameter - * indicates which of the set*uid system calls invoked this hook. If - * @new is the set of credentials that will be installed. Modifications - * should be made to this rather than to @current->cred. - * @old is the set of credentials that are being replaced. - * @flags contains one of the LSM_SETID_* values. - * Return 0 on success. - * @task_fix_setgid: - * Update the module's state after setting one or more of the group - * identity attributes of the current process. The @flags parameter - * indicates which of the set*gid system calls invoked this hook. - * @new is the set of credentials that will be installed. Modifications - * should be made to this rather than to @current->cred. - * @old is the set of credentials that are being replaced. - * @flags contains one of the LSM_SETID_* values. - * Return 0 on success. - * @task_fix_setgroups: - * Update the module's state after setting the supplementary group - * identity attributes of the current process. - * @new is the set of credentials that will be installed. Modifications - * should be made to this rather than to @current->cred. - * @old is the set of credentials that are being replaced. - * Return 0 on success. - * @task_setpgid: - * Check permission before setting the process group identifier of the - * process @p to @pgid. - * @p contains the task_struct for process being modified. - * @pgid contains the new pgid. - * Return 0 if permission is granted. - * @task_getpgid: - * Check permission before getting the process group identifier of the - * process @p. - * @p contains the task_struct for the process. - * Return 0 if permission is granted. - * @task_getsid: - * Check permission before getting the session identifier of the process - * @p. - * @p contains the task_struct for the process. - * Return 0 if permission is granted. - * @current_getsecid_subj: - * Retrieve the subjective security identifier of the current task and - * return it in @secid. - * In case of failure, @secid will be set to zero. - * @task_getsecid_obj: - * Retrieve the objective security identifier of the task_struct in @p - * and return it in @secid. - * In case of failure, @secid will be set to zero. - * - * @task_setnice: - * Check permission before setting the nice value of @p to @nice. - * @p contains the task_struct of process. - * @nice contains the new nice value. - * Return 0 if permission is granted. - * @task_setioprio: - * Check permission before setting the ioprio value of @p to @ioprio. - * @p contains the task_struct of process. - * @ioprio contains the new ioprio value. - * Return 0 if permission is granted. - * @task_getioprio: - * Check permission before getting the ioprio value of @p. - * @p contains the task_struct of process. - * Return 0 if permission is granted. - * @task_prlimit: - * Check permission before getting and/or setting the resource limits of - * another task. - * @cred points to the cred structure for the current task. - * @tcred points to the cred structure for the target task. - * @flags contains the LSM_PRLIMIT_* flag bits indicating whether the - * resource limits are being read, modified, or both. - * Return 0 if permission is granted. - * @task_setrlimit: - * Check permission before setting the resource limits of process @p - * for @resource to @new_rlim. The old resource limit values can - * be examined by dereferencing (p->signal->rlim + resource). - * @p points to the task_struct for the target task's group leader. - * @resource contains the resource whose limit is being set. - * @new_rlim contains the new limits for @resource. - * Return 0 if permission is granted. - * @task_setscheduler: - * Check permission before setting scheduling policy and/or parameters of - * process @p. - * @p contains the task_struct for process. - * Return 0 if permission is granted. - * @task_getscheduler: - * Check permission before obtaining scheduling information for process - * @p. - * @p contains the task_struct for process. - * Return 0 if permission is granted. - * @task_movememory: - * Check permission before moving memory owned by process @p. - * @p contains the task_struct for process. - * Return 0 if permission is granted. - * @task_kill: - * Check permission before sending signal @sig to @p. @info can be NULL, - * the constant 1, or a pointer to a kernel_siginfo structure. If @info is 1 or - * SI_FROMKERNEL(info) is true, then the signal should be viewed as coming - * from the kernel and should typically be permitted. - * SIGIO signals are handled separately by the send_sigiotask hook in - * file_security_ops. - * @p contains the task_struct for process. - * @info contains the signal information. - * @sig contains the signal value. - * @cred contains the cred of the process where the signal originated, or - * NULL if the current task is the originator. - * Return 0 if permission is granted. - * @task_prctl: - * Check permission before performing a process control operation on the - * current process. - * @option contains the operation. - * @arg2 contains a argument. - * @arg3 contains a argument. - * @arg4 contains a argument. - * @arg5 contains a argument. - * Return -ENOSYS if no-one wanted to handle this op, any other value to - * cause prctl() to return immediately with that value. - * @task_to_inode: - * Set the security attributes for an inode based on an associated task's - * security attributes, e.g. for /proc/pid inodes. - * @p contains the task_struct for the task. - * @inode contains the inode structure for the inode. - * @userns_create: - * Check permission prior to creating a new user namespace. - * @cred points to prepared creds. - * Return 0 if successful, otherwise < 0 error code. - * * Security hooks for Netlink messaging. * * @netlink_send: diff --git a/security/security.c b/security/security.c index a527291c191d..766595a76ab4 100644 --- a/security/security.c +++ b/security/security.c @@ -2656,6 +2656,15 @@ int security_file_truncate(struct file *file) return call_int_hook(file_truncate, 0, file); } +/** + * security_task_alloc() - Allocate a task's LSM blob + * @task: the task + * @clone_flags: flags indicating what is being shared + * + * Handle allocation of task-related resources. + * + * Return: Returns a zero on success, negative values on failure. + */ int security_task_alloc(struct task_struct *task, unsigned long clone_flags) { int rc = lsm_task_alloc(task); @@ -2668,6 +2677,13 @@ int security_task_alloc(struct task_struct *task, unsigned long clone_flags) return rc; } +/** + * security_task_free() - Free a task's LSM blob and related resources + * @task: task + * + * Handle release of task-related resources. Note that this can be called from + * interrupt context. + */ void security_task_free(struct task_struct *task) { call_void_hook(task_free, task); @@ -2676,6 +2692,16 @@ void security_task_free(struct task_struct *task) task->security = NULL; } +/** + * security_cred_alloc_blank() - Allocate the min memory to allow cred_transfer + * @cred: credentials + * @gfp: gfp flags + * + * Only allocate sufficient memory and attach to @cred such that + * cred_transfer() will not get ENOMEM. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) { int rc = lsm_cred_alloc(cred, gfp); @@ -2689,6 +2715,12 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) return rc; } +/** + * security_cred_free() - Free the cred's LSM blob and associated resources + * @cred: credentials + * + * Deallocate and clear the cred->security field in a set of credentials. + */ void security_cred_free(struct cred *cred) { /* @@ -2704,6 +2736,16 @@ void security_cred_free(struct cred *cred) cred->security = NULL; } +/** + * security_prepare_creds() - Prepare a new set of credentials + * @new: new credentials + * @old: original credentials + * @gfp: gfp flags + * + * Prepare a new set of credentials by copying the data from the old set. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) { int rc = lsm_cred_alloc(new, gfp); @@ -2717,11 +2759,26 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) return rc; } +/** + * security_transfer_creds() - Transfer creds + * @new: target credentials + * @old: original credentials + * + * Transfer data from original creds to new creds. + */ void security_transfer_creds(struct cred *new, const struct cred *old) { call_void_hook(cred_transfer, new, old); } +/** + * security_cred_getsecid() - Get the secid from a set of credentials + * @c: credentials + * @secid: secid value + * + * Retrieve the security identifier of the cred structure @c. In case of + * failure, @secid will be set to zero. + */ void security_cred_getsecid(const struct cred *c, u32 *secid) { *secid = 0; @@ -2729,16 +2786,46 @@ void security_cred_getsecid(const struct cred *c, u32 *secid) } EXPORT_SYMBOL(security_cred_getsecid); +/** + * security_kernel_act_as() - Set the kernel credentials to act as secid + * @new: credentials + * @secid: secid + * + * Set the credentials for a kernel service to act as (subjective context). + * The current task must be the one that nominated @secid. + * + * Return: Returns 0 if successful. + */ int security_kernel_act_as(struct cred *new, u32 secid) { return call_int_hook(kernel_act_as, 0, new, secid); } +/** + * security_kernel_create_files_as() - Set file creation context using an inode + * @new: target credentials + * @inode: reference inode + * + * Set the file creation context in a set of credentials to be the same as the + * objective context of the specified inode. The current task must be the one + * that nominated @inode. + * + * Return: Returns 0 if successful. + */ int security_kernel_create_files_as(struct cred *new, struct inode *inode) { return call_int_hook(kernel_create_files_as, 0, new, inode); } +/** + * security_kernel_module_request() - Check is loading a module is allowed + * @kmod_name: module name + * + * Ability to trigger the kernel to automatically upcall to userspace for + * userspace to load a kernel module with the given name. + * + * Return: Returns 0 if successful. + */ int security_kernel_module_request(char *kmod_name) { int ret; @@ -2749,6 +2836,16 @@ int security_kernel_module_request(char *kmod_name) return integrity_kernel_module_request(kmod_name); } +/** + * security_kernel_read_file() - Read a file specified by userspace + * @file: file + * @id: file identifier + * @contents: trust if security_kernel_post_read_file() will be called + * + * Read a file specified by userspace. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_read_file(struct file *file, enum kernel_read_file_id id, bool contents) { @@ -2761,6 +2858,19 @@ int security_kernel_read_file(struct file *file, enum kernel_read_file_id id, } EXPORT_SYMBOL_GPL(security_kernel_read_file); +/** + * security_kernel_post_read_file() - Read a file specified by userspace + * @file: file + * @buf: file contents + * @size: size of file contents + * @id: file identifier + * + * Read a file specified by userspace. This must be paired with a prior call + * to security_kernel_read_file() call that indicated this hook would also be + * called, see security_kernel_read_file() for more information. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id) { @@ -2773,6 +2883,15 @@ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, } EXPORT_SYMBOL_GPL(security_kernel_post_read_file); +/** + * security_kernel_load_data() - Load data provided by userspace + * @id: data identifier + * @contents: true if security_kernel_post_load_data() will be called + * + * Load data provided by userspace. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_load_data(enum kernel_load_data_id id, bool contents) { int ret; @@ -2784,6 +2903,20 @@ int security_kernel_load_data(enum kernel_load_data_id id, bool contents) } EXPORT_SYMBOL_GPL(security_kernel_load_data); +/** + * security_kernel_post_load_data() - Load userspace data from a non-file source + * @buf: data + * @size: size of data + * @id: data identifier + * @description: text description of data, specific to the id value + * + * Load data provided by a non-file source (usually userspace buffer). This + * must be paired with a prior security_kernel_load_data() call that indicated + * this hook would also be called, see security_kernel_load_data() for more + * information. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_post_load_data(char *buf, loff_t size, enum kernel_load_data_id id, char *description) @@ -2798,38 +2931,112 @@ int security_kernel_post_load_data(char *buf, loff_t size, } EXPORT_SYMBOL_GPL(security_kernel_post_load_data); +/** + * security_task_fix_setuid() - Update LSM with new user id attributes + * @new: updated credentials + * @old: credentials being replaced + * @flags: LSM_SETID_* flag values + * + * Update the module's state after setting one or more of the user identity + * attributes of the current process. The @flags parameter indicates which of + * the set*uid system calls invoked this hook. If @new is the set of + * credentials that will be installed. Modifications should be made to this + * rather than to @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { return call_int_hook(task_fix_setuid, 0, new, old, flags); } +/** + * security_task_fix_setgid() - Update LSM with new group id attributes + * @new: updated credentials + * @old: credentials being replaced + * @flags: LSM_SETID_* flag value + * + * Update the module's state after setting one or more of the group identity + * attributes of the current process. The @flags parameter indicates which of + * the set*gid system calls invoked this hook. @new is the set of credentials + * that will be installed. Modifications should be made to this rather than to + * @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setgid(struct cred *new, const struct cred *old, int flags) { return call_int_hook(task_fix_setgid, 0, new, old, flags); } +/** + * security_task_fix_setgroups() - Update LSM with new supplementary groups + * @new: updated credentials + * @old: credentials being replaced + * + * Update the module's state after setting the supplementary group identity + * attributes of the current process. @new is the set of credentials that will + * be installed. Modifications should be made to this rather than to + * @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setgroups(struct cred *new, const struct cred *old) { return call_int_hook(task_fix_setgroups, 0, new, old); } +/** + * security_task_setpgid() - Check if setting the pgid is allowed + * @p: task being modified + * @pgid: new pgid + * + * Check permission before setting the process group identifier of the process + * @p to @pgid. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setpgid(struct task_struct *p, pid_t pgid) { return call_int_hook(task_setpgid, 0, p, pgid); } +/** + * security_task_getpgid() - Check if getting the pgid is allowed + * @p: task + * + * Check permission before getting the process group identifier of the process + * @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getpgid(struct task_struct *p) { return call_int_hook(task_getpgid, 0, p); } +/** + * security_task_getsid() - Check if getting the session id is allowed + * @p: task + * + * Check permission before getting the session identifier of the process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getsid(struct task_struct *p) { return call_int_hook(task_getsid, 0, p); } +/** + * security_current_getsecid_subj() - Get the current task's subjective secid + * @secid: secid value + * + * Retrieve the subjective security identifier of the current task and return + * it in @secid. In case of failure, @secid will be set to zero. + */ void security_current_getsecid_subj(u32 *secid) { *secid = 0; @@ -2837,6 +3044,14 @@ void security_current_getsecid_subj(u32 *secid) } EXPORT_SYMBOL(security_current_getsecid_subj); +/** + * security_task_getsecid_obj() - Get a task's objective secid + * @p: target task + * @secid: secid value + * + * Retrieve the objective security identifier of the task_struct in @p and + * return it in @secid. In case of failure, @secid will be set to zero. + */ void security_task_getsecid_obj(struct task_struct *p, u32 *secid) { *secid = 0; @@ -2844,54 +3059,157 @@ void security_task_getsecid_obj(struct task_struct *p, u32 *secid) } EXPORT_SYMBOL(security_task_getsecid_obj); +/** + * security_task_setnice() - Check if setting a task's nice value is allowed + * @p: target task + * @nice: nice value + * + * Check permission before setting the nice value of @p to @nice. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setnice(struct task_struct *p, int nice) { return call_int_hook(task_setnice, 0, p, nice); } +/** + * security_task_setioprio() - Check if setting a task's ioprio is allowed + * @p: target task + * @ioprio: ioprio value + * + * Check permission before setting the ioprio value of @p to @ioprio. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setioprio(struct task_struct *p, int ioprio) { return call_int_hook(task_setioprio, 0, p, ioprio); } +/** + * security_task_getioprio() - Check if getting a task's ioprio is allowed + * @p: task + * + * Check permission before getting the ioprio value of @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getioprio(struct task_struct *p) { return call_int_hook(task_getioprio, 0, p); } +/** + * security_task_prlimit() - Check if get/setting resources limits is allowed + * @cred: current task credentials + * @tcred: target task credentials + * @flags: LSM_PRLIMIT_* flag bits indicating a get/set/both + * + * Check permission before getting and/or setting the resource limits of + * another task. + * + * Return: Returns 0 if permission is granted. + */ int security_task_prlimit(const struct cred *cred, const struct cred *tcred, unsigned int flags) { return call_int_hook(task_prlimit, 0, cred, tcred, flags); } +/** + * security_task_setrlimit() - Check if setting a new rlimit value is allowed + * @p: target task's group leader + * @resource: resource whose limit is being set + * @new_rlim: new resource limit + * + * Check permission before setting the resource limits of process @p for + * @resource to @new_rlim. The old resource limit values can be examined by + * dereferencing (p->signal->rlim + resource). + * + * Return: Returns 0 if permission is granted. + */ int security_task_setrlimit(struct task_struct *p, unsigned int resource, struct rlimit *new_rlim) { return call_int_hook(task_setrlimit, 0, p, resource, new_rlim); } +/** + * security_task_setscheduler() - Check if setting sched policy/param is allowed + * @p: target task + * + * Check permission before setting scheduling policy and/or parameters of + * process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setscheduler(struct task_struct *p) { return call_int_hook(task_setscheduler, 0, p); } +/** + * security_task_getscheduler() - Check if getting scheduling info is allowed + * @p: target task + * + * Check permission before obtaining scheduling information for process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getscheduler(struct task_struct *p) { return call_int_hook(task_getscheduler, 0, p); } +/** + * security_task_movememory() - Check if moving memory is allowed + * @p: task + * + * Check permission before moving memory owned by process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_movememory(struct task_struct *p) { return call_int_hook(task_movememory, 0, p); } +/** + * security_task_kill() - Check if sending a signal is allowed + * @p: target process + * @info: signal information + * @sig: signal value + * @cred: credentials of the signal sender, NULL if @current + * + * Check permission before sending signal @sig to @p. @info can be NULL, the + * constant 1, or a pointer to a kernel_siginfo structure. If @info is 1 or + * SI_FROMKERNEL(info) is true, then the signal should be viewed as coming from + * the kernel and should typically be permitted. SIGIO signals are handled + * separately by the send_sigiotask hook in file_security_ops. + * + * Return: Returns 0 if permission is granted. + */ int security_task_kill(struct task_struct *p, struct kernel_siginfo *info, int sig, const struct cred *cred) { return call_int_hook(task_kill, 0, p, info, sig, cred); } +/** + * security_task_prctl() - Check if a prctl op is allowed + * @option: operation + * @arg2: argument + * @arg3: argument + * @arg4: argument + * @arg5: argument + * + * Check permission before performing a process control operation on the + * current process. + * + * Return: Return -ENOSYS if no-one wanted to handle this op, any other value + * to cause prctl() to return immediately with that value. + */ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { @@ -2910,11 +3228,27 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, return rc; } +/** + * security_task_to_inode() - Set the security attributes of a task's inode + * @p: task + * @inode: inode + * + * Set the security attributes for an inode based on an associated task's + * security attributes, e.g. for /proc/pid inodes. + */ void security_task_to_inode(struct task_struct *p, struct inode *inode) { call_void_hook(task_to_inode, p, inode); } +/** + * security_create_user_ns() - Check if creating a new userns is allowed + * @cred: prepared creds + * + * Check permission prior to creating a new user namespace. + * + * Return: Returns 0 if successful, otherwise < 0 error code. + */ int security_create_user_ns(const struct cred *cred) { return call_int_hook(userns_create, 0, cred); From 2bcf51bf2f03cc9fccd3316d361cdf9695fccd11 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Sun, 12 Feb 2023 15:06:59 -0500 Subject: [PATCH 08/32] lsm: move the netlink hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 13 ------------- security/security.c | 13 +++++++++++++ 2 files changed, 13 insertions(+), 13 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 5578a13729bd..ba2daec1bc35 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,19 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for Netlink messaging. - * - * @netlink_send: - * Save security information for a netlink message so that permission - * checking can be performed when the message is processed. The security - * information can be saved using the eff_cap field of the - * netlink_skb_parms structure. Also may be used to provide fine - * grained control over message transmission. - * @sk associated sock of task sending the message. - * @skb contains the sk_buff structure for the netlink message. - * Return 0 if the information was successfully saved and message - * is allowed to be transmitted. - * * Security hooks for Unix domain networking. * * @unix_stream_connect: diff --git a/security/security.c b/security/security.c index 766595a76ab4..b5fe49ac564e 100644 --- a/security/security.c +++ b/security/security.c @@ -3458,6 +3458,19 @@ int security_setprocattr(const char *lsm, const char *name, void *value, return LSM_RET_DEFAULT(setprocattr); } +/** + * security_netlink_send() - Save info and check if netlink sending is allowed + * @sk: sending socket + * @skb: netlink message + * + * Save security information for a netlink message so that permission checking + * can be performed when the message is processed. The security information + * can be saved using the eff_cap field of the netlink_skb_parms structure. + * Also may be used to provide fine grained control over message transmission. + * + * Return: Returns 0 if the information was successfully saved and message is + * allowed to be transmitted. + */ int security_netlink_send(struct sock *sk, struct sk_buff *skb) { return call_int_hook(netlink_send, 0, sk, skb); From 2c2442fd46cd162c0b6a07b4560095f03bd3275f Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Sun, 12 Feb 2023 15:10:23 -0500 Subject: [PATCH 09/32] lsm: move the AF_UNIX hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 26 ------------------------ security/security.c | 42 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 41 insertions(+), 27 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index ba2daec1bc35..1fc1e2aa7d01 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,32 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for Unix domain networking. - * - * @unix_stream_connect: - * Check permissions before establishing a Unix domain stream connection - * between @sock and @other. - * @sock contains the sock structure. - * @other contains the peer sock structure. - * @newsk contains the new sock structure. - * Return 0 if permission is granted. - * @unix_may_send: - * Check permissions before connecting or sending datagrams from @sock to - * @other. - * @sock contains the socket structure. - * @other contains the peer socket structure. - * Return 0 if permission is granted. - * - * The @unix_stream_connect and @unix_may_send hooks were necessary because - * Linux provides an alternative to the conventional file name space for Unix - * domain sockets. Whereas binding and connecting to sockets in the file name - * space is mediated by the typical file permissions (and caught by the mknod - * and permission hooks in inode_security_ops), binding and connecting to - * sockets in the abstract name space is completely unmediated. Sufficient - * control of Unix domain sockets in the abstract name space isn't possible - * using only the socket layer hooks, since we need to know the actual target - * socket, which is not looked up until we are inside the af_unix code. - * * Security hooks for socket operations. * * @socket_create: diff --git a/security/security.c b/security/security.c index b5fe49ac564e..9112531e6c2e 100644 --- a/security/security.c +++ b/security/security.c @@ -3555,13 +3555,53 @@ int security_watch_key(struct key *key) #endif #ifdef CONFIG_SECURITY_NETWORK - +/** + * security_unix_stream_connect() - Check if a AF_UNIX stream is allowed + * @sock: originating sock + * @other: peer sock + * @newsk: new sock + * + * Check permissions before establishing a Unix domain stream connection + * between @sock and @other. + * + * The @unix_stream_connect and @unix_may_send hooks were necessary because + * Linux provides an alternative to the conventional file name space for Unix + * domain sockets. Whereas binding and connecting to sockets in the file name + * space is mediated by the typical file permissions (and caught by the mknod + * and permission hooks in inode_security_ops), binding and connecting to + * sockets in the abstract name space is completely unmediated. Sufficient + * control of Unix domain sockets in the abstract name space isn't possible + * using only the socket layer hooks, since we need to know the actual target + * socket, which is not looked up until we are inside the af_unix code. + * + * Return: Returns 0 if permission is granted. + */ int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk) { return call_int_hook(unix_stream_connect, 0, sock, other, newsk); } EXPORT_SYMBOL(security_unix_stream_connect); +/** + * security_unix_may_send() - Check if AF_UNIX socket can send datagrams + * @sock: originating sock + * @other: peer sock + * + * Check permissions before connecting or sending datagrams from @sock to + * @other. + * + * The @unix_stream_connect and @unix_may_send hooks were necessary because + * Linux provides an alternative to the conventional file name space for Unix + * domain sockets. Whereas binding and connecting to sockets in the file name + * space is mediated by the typical file permissions (and caught by the mknod + * and permission hooks in inode_security_ops), binding and connecting to + * sockets in the abstract name space is completely unmediated. Sufficient + * control of Unix domain sockets in the abstract name space isn't possible + * using only the socket layer hooks, since we need to know the actual target + * socket, which is not looked up until we are inside the af_unix code. + * + * Return: Returns 0 if permission is granted. + */ int security_unix_may_send(struct socket *sock, struct socket *other) { return call_int_hook(unix_may_send, 0, sock, other); From 6b6bbe8c02a1bc7ef7f0aa490a3601a16cd145fe Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Sun, 12 Feb 2023 15:15:29 -0500 Subject: [PATCH 10/32] lsm: move the socket hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 191 ---------------------- security/security.c | 322 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 322 insertions(+), 191 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 1fc1e2aa7d01..531d141083ed 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,197 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for socket operations. - * - * @socket_create: - * Check permissions prior to creating a new socket. - * @family contains the requested protocol family. - * @type contains the requested communications type. - * @protocol contains the requested protocol. - * @kern set to 1 if a kernel socket. - * Return 0 if permission is granted. - * @socket_post_create: - * This hook allows a module to update or allocate a per-socket security - * structure. Note that the security field was not added directly to the - * socket structure, but rather, the socket security information is stored - * in the associated inode. Typically, the inode alloc_security hook will - * allocate and attach security information to - * SOCK_INODE(sock)->i_security. This hook may be used to update the - * SOCK_INODE(sock)->i_security field with additional information that - * wasn't available when the inode was allocated. - * @sock contains the newly created socket structure. - * @family contains the requested protocol family. - * @type contains the requested communications type. - * @protocol contains the requested protocol. - * @kern set to 1 if a kernel socket. - * Return 0 if permission is granted. - * @socket_socketpair: - * Check permissions before creating a fresh pair of sockets. - * @socka contains the first socket structure. - * @sockb contains the second socket structure. - * Return 0 if permission is granted and the connection was established. - * @socket_bind: - * Check permission before socket protocol layer bind operation is - * performed and the socket @sock is bound to the address specified in the - * @address parameter. - * @sock contains the socket structure. - * @address contains the address to bind to. - * @addrlen contains the length of address. - * Return 0 if permission is granted. - * @socket_connect: - * Check permission before socket protocol layer connect operation - * attempts to connect socket @sock to a remote address, @address. - * @sock contains the socket structure. - * @address contains the address of remote endpoint. - * @addrlen contains the length of address. - * Return 0 if permission is granted. - * @socket_listen: - * Check permission before socket protocol layer listen operation. - * @sock contains the socket structure. - * @backlog contains the maximum length for the pending connection queue. - * Return 0 if permission is granted. - * @socket_accept: - * Check permission before accepting a new connection. Note that the new - * socket, @newsock, has been created and some information copied to it, - * but the accept operation has not actually been performed. - * @sock contains the listening socket structure. - * @newsock contains the newly created server socket for connection. - * Return 0 if permission is granted. - * @socket_sendmsg: - * Check permission before transmitting a message to another socket. - * @sock contains the socket structure. - * @msg contains the message to be transmitted. - * @size contains the size of message. - * Return 0 if permission is granted. - * @socket_recvmsg: - * Check permission before receiving a message from a socket. - * @sock contains the socket structure. - * @msg contains the message structure. - * @size contains the size of message structure. - * @flags contains the operational flags. - * Return 0 if permission is granted. - * @socket_getsockname: - * Check permission before the local address (name) of the socket object - * @sock is retrieved. - * @sock contains the socket structure. - * Return 0 if permission is granted. - * @socket_getpeername: - * Check permission before the remote address (name) of a socket object - * @sock is retrieved. - * @sock contains the socket structure. - * Return 0 if permission is granted. - * @socket_getsockopt: - * Check permissions before retrieving the options associated with socket - * @sock. - * @sock contains the socket structure. - * @level contains the protocol level to retrieve option from. - * @optname contains the name of option to retrieve. - * Return 0 if permission is granted. - * @socket_setsockopt: - * Check permissions before setting the options associated with socket - * @sock. - * @sock contains the socket structure. - * @level contains the protocol level to set options for. - * @optname contains the name of the option to set. - * Return 0 if permission is granted. - * @socket_shutdown: - * Checks permission before all or part of a connection on the socket - * @sock is shut down. - * @sock contains the socket structure. - * @how contains the flag indicating how future sends and receives - * are handled. - * Return 0 if permission is granted. - * @socket_sock_rcv_skb: - * Check permissions on incoming network packets. This hook is distinct - * from Netfilter's IP input hooks since it is the first time that the - * incoming sk_buff @skb has been associated with a particular socket, @sk. - * Must not sleep inside this hook because some callers hold spinlocks. - * @sk contains the sock (not socket) associated with the incoming sk_buff. - * @skb contains the incoming network data. - * Return 0 if permission is granted. - * @socket_getpeersec_stream: - * This hook allows the security module to provide peer socket security - * state for unix or connected tcp sockets to userspace via getsockopt - * SO_GETPEERSEC. For tcp sockets this can be meaningful if the - * socket is associated with an ipsec SA. - * @sock is the local socket. - * @optval memory where the security state is to be copied. - * @optlen memory where the module should copy the actual length - * of the security state. - * @len as input is the maximum length to copy to userspace provided - * by the caller. - * Return 0 if all is well, otherwise, typical getsockopt return - * values. - * @socket_getpeersec_dgram: - * This hook allows the security module to provide peer socket security - * state for udp sockets on a per-packet basis to userspace via - * getsockopt SO_GETPEERSEC. The application must first have indicated - * the IP_PASSSEC option via getsockopt. It can then retrieve the - * security state returned by this hook for a packet via the SCM_SECURITY - * ancillary message type. - * @sock contains the peer socket. May be NULL. - * @skb is the sk_buff for the packet being queried. May be NULL. - * @secid pointer to store the secid of the packet. - * Return 0 on success, error on failure. - * @sk_alloc_security: - * Allocate and attach a security structure to the sk->sk_security field, - * which is used to copy security attributes between local stream sockets. - * Return 0 on success, error on failure. - * @sk_free_security: - * Deallocate security structure. - * @sk_clone_security: - * Clone/copy security structure. - * @sk_getsecid: - * Retrieve the LSM-specific secid for the sock to enable caching - * of network authorizations. - * @sock_graft: - * Sets the socket's isec sid to the sock's sid. - * @inet_conn_request: - * Sets the openreq's sid to socket's sid with MLS portion taken - * from peer sid. - * Return 0 if permission is granted. - * @inet_csk_clone: - * Sets the new child socket's sid to the openreq sid. - * @inet_conn_established: - * Sets the connection's peersid to the secmark on skb. - * @secmark_relabel_packet: - * Check if the process should be allowed to relabel packets to - * the given secid. - * Return 0 if permission is granted. - * @secmark_refcount_inc: - * Tells the LSM to increment the number of secmark labeling rules loaded. - * @secmark_refcount_dec: - * Tells the LSM to decrement the number of secmark labeling rules loaded. - * @req_classify_flow: - * Sets the flow's sid to the openreq sid. - * @tun_dev_alloc_security: - * This hook allows a module to allocate a security structure for a TUN - * device. - * @security pointer to a security structure pointer. - * Returns a zero on success, negative values on failure. - * @tun_dev_free_security: - * This hook allows a module to free the security structure for a TUN - * device. - * @security pointer to the TUN device's security structure. - * @tun_dev_create: - * Check permissions prior to creating a new TUN device. - * Return 0 if permission is granted. - * @tun_dev_attach_queue: - * Check permissions prior to attaching to a TUN device queue. - * @security pointer to the TUN device's security structure. - * Return 0 if permission is granted. - * @tun_dev_attach: - * This hook can be used by the module to update any security state - * associated with the TUN device's sock structure. - * @sk contains the existing sock structure. - * @security pointer to the TUN device's security structure. - * Return 0 if permission is granted. - * @tun_dev_open: - * This hook can be used by the module to update any security state - * associated with the TUN device's security structure. - * @security pointer to the TUN devices's security structure. - * Return 0 if permission is granted. - * * Security hooks for SCTP * * @sctp_assoc_request: diff --git a/security/security.c b/security/security.c index 9112531e6c2e..1b2eca6437c4 100644 --- a/security/security.c +++ b/security/security.c @@ -3608,11 +3608,40 @@ int security_unix_may_send(struct socket *sock, struct socket *other) } EXPORT_SYMBOL(security_unix_may_send); +/** + * security_socket_create() - Check if creating a new socket is allowed + * @family: protocol family + * @type: communications type + * @protocol: requested protocol + * @kern: set to 1 if a kernel socket is requested + * + * Check permissions prior to creating a new socket. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_create(int family, int type, int protocol, int kern) { return call_int_hook(socket_create, 0, family, type, protocol, kern); } +/** + * security_socket_create() - Initialize a newly created socket + * @sock: socket + * @family: protocol family + * @type: communications type + * @protocol: requested protocol + * @kern: set to 1 if a kernel socket is requested + * + * This hook allows a module to update or allocate a per-socket security + * structure. Note that the security field was not added directly to the socket + * structure, but rather, the socket security information is stored in the + * associated inode. Typically, the inode alloc_security hook will allocate + * and attach security information to SOCK_INODE(sock)->i_security. This hook + * may be used to update the SOCK_INODE(sock)->i_security field with additional + * information that wasn't available when the inode was allocated. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_post_create(struct socket *sock, int family, int type, int protocol, int kern) { @@ -3620,74 +3649,223 @@ int security_socket_post_create(struct socket *sock, int family, protocol, kern); } +/** + * security_socket_socketpair() - Check if creating a socketpair is allowed + * @socka: first socket + * @sockb: second socket + * + * Check permissions before creating a fresh pair of sockets. + * + * Return: Returns 0 if permission is granted and the connection was + * established. + */ int security_socket_socketpair(struct socket *socka, struct socket *sockb) { return call_int_hook(socket_socketpair, 0, socka, sockb); } EXPORT_SYMBOL(security_socket_socketpair); +/** + * security_socket_bind() - Check if a socket bind operation is allowed + * @sock: socket + * @address: requested bind address + * @addrlen: length of address + * + * Check permission before socket protocol layer bind operation is performed + * and the socket @sock is bound to the address specified in the @address + * parameter. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) { return call_int_hook(socket_bind, 0, sock, address, addrlen); } +/** + * security_socket_connect() - Check if a socket connect operation is allowed + * @sock: socket + * @address: address of remote connection point + * @addrlen: length of address + * + * Check permission before socket protocol layer connect operation attempts to + * connect socket @sock to a remote address, @address. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) { return call_int_hook(socket_connect, 0, sock, address, addrlen); } +/** + * security_socket_listen() - Check if a socket is allowed to listen + * @sock: socket + * @backlog: connection queue size + * + * Check permission before socket protocol layer listen operation. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_listen(struct socket *sock, int backlog) { return call_int_hook(socket_listen, 0, sock, backlog); } +/** + * security_socket_accept() - Check if a socket is allowed to accept connections + * @sock: listening socket + * @newsock: newly creation connection socket + * + * Check permission before accepting a new connection. Note that the new + * socket, @newsock, has been created and some information copied to it, but + * the accept operation has not actually been performed. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_accept(struct socket *sock, struct socket *newsock) { return call_int_hook(socket_accept, 0, sock, newsock); } +/** + * security_socket_sendmsg() - Check is sending a message is allowed + * @sock: sending socket + * @msg: message to send + * @size: size of message + * + * Check permission before transmitting a message to another socket. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_sendmsg(struct socket *sock, struct msghdr *msg, int size) { return call_int_hook(socket_sendmsg, 0, sock, msg, size); } +/** + * security_socket_recvmsg() - Check if receiving a message is allowed + * @sock: receiving socket + * @msg: message to receive + * @size: size of message + * @flags: operational flags + * + * Check permission before receiving a message from a socket. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_recvmsg(struct socket *sock, struct msghdr *msg, int size, int flags) { return call_int_hook(socket_recvmsg, 0, sock, msg, size, flags); } +/** + * security_socket_getsockname() - Check if reading the socket addr is allowed + * @sock: socket + * + * Check permission before reading the local address (name) of the socket + * object. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_getsockname(struct socket *sock) { return call_int_hook(socket_getsockname, 0, sock); } +/** + * security_socket_getpeername() - Check if reading the peer's addr is allowed + * @sock: socket + * + * Check permission before the remote address (name) of a socket object. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_getpeername(struct socket *sock) { return call_int_hook(socket_getpeername, 0, sock); } +/** + * security_socket_getsockopt() - Check if reading a socket option is allowed + * @sock: socket + * @level: option's protocol level + * @optname: option name + * + * Check permissions before retrieving the options associated with socket + * @sock. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_getsockopt(struct socket *sock, int level, int optname) { return call_int_hook(socket_getsockopt, 0, sock, level, optname); } +/** + * security_socket_setsockopt() - Check if setting a socket option is allowed + * @sock: socket + * @level: option's protocol level + * @optname: option name + * + * Check permissions before setting the options associated with socket @sock. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_setsockopt(struct socket *sock, int level, int optname) { return call_int_hook(socket_setsockopt, 0, sock, level, optname); } +/** + * security_socket_shutdown() - Checks if shutting down the socket is allowed + * @sock: socket + * @how: flag indicating how sends and receives are handled + * + * Checks permission before all or part of a connection on the socket @sock is + * shut down. + * + * Return: Returns 0 if permission is granted. + */ int security_socket_shutdown(struct socket *sock, int how) { return call_int_hook(socket_shutdown, 0, sock, how); } +/** + * security_sock_rcv_skb() - Check if an incoming network packet is allowed + * @sk: destination sock + * @skb: incoming packet + * + * Check permissions on incoming network packets. This hook is distinct from + * Netfilter's IP input hooks since it is the first time that the incoming + * sk_buff @skb has been associated with a particular socket, @sk. Must not + * sleep inside this hook because some callers hold spinlocks. + * + * Return: Returns 0 if permission is granted. + */ int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { return call_int_hook(socket_sock_rcv_skb, 0, sk, skb); } EXPORT_SYMBOL(security_sock_rcv_skb); +/** + * security_socket_getpeersec_stream() - Get the remote peer label + * @sock: socket + * @optval: destination buffer + * @optlen: size of peer label copied into the buffer + * @len: maximum size of the destination buffer + * + * This hook allows the security module to provide peer socket security state + * for unix or connected tcp sockets to userspace via getsockopt SO_GETPEERSEC. + * For tcp sockets this can be meaningful if the socket is associated with an + * ipsec SA. + * + * Return: Returns 0 if all is well, otherwise, typical getsockopt return + * values. + */ int security_socket_getpeersec_stream(struct socket *sock, sockptr_t optval, sockptr_t optlen, unsigned int len) { @@ -3695,6 +3873,20 @@ int security_socket_getpeersec_stream(struct socket *sock, sockptr_t optval, optval, optlen, len); } +/** + * security_socket_getpeersec_dgram() - Get the remote peer label + * @sock: socket + * @skb: datagram packet + * @secid: remote peer label secid + * + * This hook allows the security module to provide peer socket security state + * for udp sockets on a per-packet basis to userspace via getsockopt + * SO_GETPEERSEC. The application must first have indicated the IP_PASSSEC + * option via getsockopt. It can then retrieve the security state returned by + * this hook for a packet via the SCM_SECURITY ancillary message type. + * + * Return: Returns 0 on success, error on failure. + */ int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) { return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock, @@ -3702,16 +3894,40 @@ int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u } EXPORT_SYMBOL(security_socket_getpeersec_dgram); +/** + * security_sk_alloc() - Allocate and initialize a sock's LSM blob + * @sk: sock + * @family: protocol family + * @priotity: gfp flags + * + * Allocate and attach a security structure to the sk->sk_security field, which + * is used to copy security attributes between local stream sockets. + * + * Return: Returns 0 on success, error on failure. + */ int security_sk_alloc(struct sock *sk, int family, gfp_t priority) { return call_int_hook(sk_alloc_security, 0, sk, family, priority); } +/** + * security_sk_free() - Free the sock's LSM blob + * @sk: sock + * + * Deallocate security structure. + */ void security_sk_free(struct sock *sk) { call_void_hook(sk_free_security, sk); } +/** + * security_sk_clone() - Clone a sock's LSM state + * @sk: original sock + * @newsk: target sock + * + * Clone/copy security structure. + */ void security_sk_clone(const struct sock *sk, struct sock *newsk) { call_void_hook(sk_clone_security, sk, newsk); @@ -3724,6 +3940,13 @@ void security_sk_classify_flow(struct sock *sk, struct flowi_common *flic) } EXPORT_SYMBOL(security_sk_classify_flow); +/** + * security_req_classify_flow() - Set a flow's secid based on request_sock + * @req: request_sock + * @flic: target flow + * + * Sets @flic's secid to @req's secid. + */ void security_req_classify_flow(const struct request_sock *req, struct flowi_common *flic) { @@ -3731,12 +3954,30 @@ void security_req_classify_flow(const struct request_sock *req, } EXPORT_SYMBOL(security_req_classify_flow); +/** + * security_sock_graft() - Reconcile LSM state when grafting a sock on a socket + * @sk: sock being grafted + * @sock: target socket + * + * Sets @sock's inode secid to @sk's secid and update @sk with any necessary + * LSM state from @sock. + */ void security_sock_graft(struct sock *sk, struct socket *parent) { call_void_hook(sock_graft, sk, parent); } EXPORT_SYMBOL(security_sock_graft); +/** + * security_inet_conn_request() - Set request_sock state using incoming connect + * @sk: parent listening sock + * @skb: incoming connection + * @req: new request_sock + * + * Initialize the @req LSM state based on @sk and the incoming connect in @skb. + * + * Return: Returns 0 if permission is granted. + */ int security_inet_conn_request(const struct sock *sk, struct sk_buff *skb, struct request_sock *req) { @@ -3744,12 +3985,26 @@ int security_inet_conn_request(const struct sock *sk, } EXPORT_SYMBOL(security_inet_conn_request); +/** + * security_inet_csk_clone() - Set new sock LSM state based on request_sock + * @newsk: new sock + * @req: connection request_sock + * + * Set that LSM state of @sock using the LSM state from @req. + */ void security_inet_csk_clone(struct sock *newsk, const struct request_sock *req) { call_void_hook(inet_csk_clone, newsk, req); } +/** + * security_inet_conn_established() - Update sock's LSM state with connection + * @sk: sock + * @skb: connection packet + * + * Update @sock's LSM state to represent a new connection from @skb. + */ void security_inet_conn_established(struct sock *sk, struct sk_buff *skb) { @@ -3757,54 +4012,121 @@ void security_inet_conn_established(struct sock *sk, } EXPORT_SYMBOL(security_inet_conn_established); +/** + * security_secmark_relabel_packet() - Check if setting a secmark is allowed + * @secid: new secmark value + * + * Check if the process should be allowed to relabel packets to @secid. + * + * Return: Returns 0 if permission is granted. + */ int security_secmark_relabel_packet(u32 secid) { return call_int_hook(secmark_relabel_packet, 0, secid); } EXPORT_SYMBOL(security_secmark_relabel_packet); +/** + * security_secmark_refcount_inc() - Increment the secmark labeling rule count + * + * Tells the LSM to increment the number of secmark labeling rules loaded. + */ void security_secmark_refcount_inc(void) { call_void_hook(secmark_refcount_inc); } EXPORT_SYMBOL(security_secmark_refcount_inc); +/** + * security_secmark_refcount_dec() - Decrement the secmark labeling rule count + * + * Tells the LSM to decrement the number of secmark labeling rules loaded. + */ void security_secmark_refcount_dec(void) { call_void_hook(secmark_refcount_dec); } EXPORT_SYMBOL(security_secmark_refcount_dec); +/** + * security_tun_dev_alloc_security() - Allocate a LSM blob for a TUN device + * @security: pointer to the LSM blob + * + * This hook allows a module to allocate a security structure for a TUN device, + * returning the pointer in @security. + * + * Return: Returns a zero on success, negative values on failure. + */ int security_tun_dev_alloc_security(void **security) { return call_int_hook(tun_dev_alloc_security, 0, security); } EXPORT_SYMBOL(security_tun_dev_alloc_security); +/** + * security_tun_dev_free_security() - Free a TUN device LSM blob + * @security: LSM blob + * + * This hook allows a module to free the security structure for a TUN device. + */ void security_tun_dev_free_security(void *security) { call_void_hook(tun_dev_free_security, security); } EXPORT_SYMBOL(security_tun_dev_free_security); +/** + * security_tun_dev_create() - Check if creating a TUN device is allowed + * + * Check permissions prior to creating a new TUN device. + * + * Return: Returns 0 if permission is granted. + */ int security_tun_dev_create(void) { return call_int_hook(tun_dev_create, 0); } EXPORT_SYMBOL(security_tun_dev_create); +/** + * security_tun_dev_attach_queue() - Check if attaching a TUN queue is allowed + * @security: TUN device LSM blob + * + * Check permissions prior to attaching to a TUN device queue. + * + * Return: Returns 0 if permission is granted. + */ int security_tun_dev_attach_queue(void *security) { return call_int_hook(tun_dev_attach_queue, 0, security); } EXPORT_SYMBOL(security_tun_dev_attach_queue); +/** + * security_tun_dev_attach() - Update TUN device LSM state on attach + * @sk: associated sock + * @security: TUN device LSM blob + * + * This hook can be used by the module to update any security state associated + * with the TUN device's sock structure. + * + * Return: Returns 0 if permission is granted. + */ int security_tun_dev_attach(struct sock *sk, void *security) { return call_int_hook(tun_dev_attach, 0, sk, security); } EXPORT_SYMBOL(security_tun_dev_attach); +/** + * security_tun_dev_open() - Update TUN device LSM state on open + * @security: TUN device LSM blob + * + * This hook can be used by the module to update any security state associated + * with the TUN device's security structure. + * + * Return: Returns 0 if permission is granted. + */ int security_tun_dev_open(void *security) { return call_int_hook(tun_dev_open, 0, security); From 4a49f592e931962ab3feb9fbb43bea719517670d Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 15 Feb 2023 17:47:10 -0500 Subject: [PATCH 11/32] lsm: move the SCTP hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 33 ------------------------------ security/security.c | 43 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+), 33 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 531d141083ed..bb460e0b1ff2 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,39 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for SCTP - * - * @sctp_assoc_request: - * Passes the @asoc and @chunk->skb of the association INIT packet to - * the security module. - * @asoc pointer to sctp association structure. - * @skb pointer to skbuff of association packet. - * Return 0 on success, error on failure. - * @sctp_bind_connect: - * Validiate permissions required for each address associated with sock - * @sk. Depending on @optname, the addresses will be treated as either - * for a connect or bind service. The @addrlen is calculated on each - * ipv4 and ipv6 address using sizeof(struct sockaddr_in) or - * sizeof(struct sockaddr_in6). - * @sk pointer to sock structure. - * @optname name of the option to validate. - * @address list containing one or more ipv4/ipv6 addresses. - * @addrlen total length of address(s). - * Return 0 on success, error on failure. - * @sctp_sk_clone: - * Called whenever a new socket is created by accept(2) (i.e. a TCP - * style socket) or when a socket is 'peeled off' e.g userspace - * calls sctp_peeloff(3). - * @asoc pointer to current sctp association structure. - * @sk pointer to current sock structure. - * @newsk pointer to new sock structure. - * @sctp_assoc_established: - * Passes the @asoc and @chunk->skb of the association COOKIE_ACK packet - * to the security module. - * @asoc pointer to sctp association structure. - * @skb pointer to skbuff of association packet. - * Return 0 if permission is granted. - * * Security hooks for Infiniband * * @ib_pkey_access: diff --git a/security/security.c b/security/security.c index 1b2eca6437c4..4f57c49bf561 100644 --- a/security/security.c +++ b/security/security.c @@ -4133,12 +4133,35 @@ int security_tun_dev_open(void *security) } EXPORT_SYMBOL(security_tun_dev_open); +/** + * security_sctp_assoc_request() - Update the LSM on a SCTP association req + * @asoc: SCTP association + * @skb: packet requesting the association + * + * Passes the @asoc and @chunk->skb of the association INIT packet to the LSM. + * + * Return: Returns 0 on success, error on failure. + */ int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) { return call_int_hook(sctp_assoc_request, 0, asoc, skb); } EXPORT_SYMBOL(security_sctp_assoc_request); +/** + * security_sctp_bind_connect() - Validate a list of addrs for a SCTP option + * @sk: socket + * @optname: SCTP option to validate + * @address: list of IP addresses to validate + * @addrlen: length of the address list + * + * Validiate permissions required for each address associated with sock @sk. + * Depending on @optname, the addresses will be treated as either a connect or + * bind service. The @addrlen is calculated on each IPv4 and IPv6 address using + * sizeof(struct sockaddr_in) or sizeof(struct sockaddr_in6). + * + * Return: Returns 0 on success, error on failure. + */ int security_sctp_bind_connect(struct sock *sk, int optname, struct sockaddr *address, int addrlen) { @@ -4147,6 +4170,16 @@ int security_sctp_bind_connect(struct sock *sk, int optname, } EXPORT_SYMBOL(security_sctp_bind_connect); +/** + * security_sctp_sk_clone() - Clone a SCTP sock's LSM state + * @asoc: SCTP association + * @sk: original sock + * @newsk: target sock + * + * Called whenever a new socket is created by accept(2) (i.e. a TCP style + * socket) or when a socket is 'peeled off' e.g userspace calls + * sctp_peeloff(3). + */ void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, struct sock *newsk) { @@ -4154,6 +4187,16 @@ void security_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk, } EXPORT_SYMBOL(security_sctp_sk_clone); +/** + * security_sctp_assoc_established() - Update LSM state when assoc established + * @asoc: SCTP association + * @skb: packet establishing the association + * + * Passes the @asoc and @chunk->skb of the association COOKIE_ACK packet to the + * security module. + * + * Return: Returns 0 if permission is granted. + */ int security_sctp_assoc_established(struct sctp_association *asoc, struct sk_buff *skb) { From ac318aed54987e6bd52dba90dd2ea3dca725b5c0 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 15 Feb 2023 18:07:41 -0500 Subject: [PATCH 12/32] lsm: move the Infiniband hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 22 ---------------------- security/security.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 22 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index bb460e0b1ff2..9fc6417af980 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,28 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for Infiniband - * - * @ib_pkey_access: - * Check permission to access a pkey when modifing a QP. - * @subnet_prefix the subnet prefix of the port being used. - * @pkey the pkey to be accessed. - * @sec pointer to a security structure. - * Return 0 if permission is granted. - * @ib_endport_manage_subnet: - * Check permissions to send and receive SMPs on a end port. - * @dev_name the IB device name (i.e. mlx4_0). - * @port_num the port number. - * @sec pointer to a security structure. - * Return 0 if permission is granted. - * @ib_alloc_security: - * Allocate a security structure for Infiniband objects. - * @sec pointer to a security structure pointer. - * Returns 0 on success, non-zero on failure. - * @ib_free_security: - * Deallocate an Infiniband security structure. - * @sec contains the security structure to be freed. - * * Security hooks for XFRM operations. * * @xfrm_policy_alloc_security: diff --git a/security/security.c b/security/security.c index 4f57c49bf561..6e786e277a7f 100644 --- a/security/security.c +++ b/security/security.c @@ -4208,24 +4208,58 @@ EXPORT_SYMBOL(security_sctp_assoc_established); #ifdef CONFIG_SECURITY_INFINIBAND +/** + * security_ib_pkey_access() - Check if access to an IB pkey is allowed + * @sec: LSM blob + * @subnet_prefix: subnet prefix of the port + * @pkey: IB pkey + * + * Check permission to access a pkey when modifing a QP. + * + * Return: Returns 0 if permission is granted. + */ int security_ib_pkey_access(void *sec, u64 subnet_prefix, u16 pkey) { return call_int_hook(ib_pkey_access, 0, sec, subnet_prefix, pkey); } EXPORT_SYMBOL(security_ib_pkey_access); +/** + * security_ib_endport_manage_subnet() - Check if SMPs traffic is allowed + * @sec: LSM blob + * @dev_name: IB device name + * @port_num: port number + * + * Check permissions to send and receive SMPs on a end port. + * + * Return: Returns 0 if permission is granted. + */ int security_ib_endport_manage_subnet(void *sec, const char *dev_name, u8 port_num) { return call_int_hook(ib_endport_manage_subnet, 0, sec, dev_name, port_num); } EXPORT_SYMBOL(security_ib_endport_manage_subnet); +/** + * security_ib_alloc_security() - Allocate an Infiniband LSM blob + * @sec: LSM blob + * + * Allocate a security structure for Infiniband objects. + * + * Return: Returns 0 on success, non-zero on failure. + */ int security_ib_alloc_security(void **sec) { return call_int_hook(ib_alloc_security, 0, sec); } EXPORT_SYMBOL(security_ib_alloc_security); +/** + * security_ib_free_security() - Free an Infiniband LSM blob + * @sec: LSM blob + * + * Deallocate an Infiniband security structure. + */ void security_ib_free_security(void *sec) { call_void_hook(ib_free_security, sec); From 742b99456e86aa3e9176fb1c7db200101876c614 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 15 Feb 2023 18:14:01 -0500 Subject: [PATCH 13/32] lsm: move the xfrm hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 73 --------------------------- security/security.c | 103 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 103 insertions(+), 73 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 9fc6417af980..9c5254e4e9d1 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,79 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for XFRM operations. - * - * @xfrm_policy_alloc_security: - * @ctxp is a pointer to the xfrm_sec_ctx being added to Security Policy - * Database used by the XFRM system. - * @sec_ctx contains the security context information being provided by - * the user-level policy update program (e.g., setkey). - * @gfp is to specify the context for the allocation. - * Allocate a security structure to the xp->security field; the security - * field is initialized to NULL when the xfrm_policy is allocated. - * Return 0 if operation was successful (memory to allocate, legal - * context). - * @xfrm_policy_clone_security: - * @old_ctx contains an existing xfrm_sec_ctx. - * @new_ctxp contains a new xfrm_sec_ctx being cloned from old. - * Allocate a security structure in new_ctxp that contains the - * information from the old_ctx structure. - * Return 0 if operation was successful (memory to allocate). - * @xfrm_policy_free_security: - * @ctx contains the xfrm_sec_ctx. - * Deallocate xp->security. - * @xfrm_policy_delete_security: - * @ctx contains the xfrm_sec_ctx. - * Authorize deletion of xp->security. - * Return 0 if permission is granted. - * @xfrm_state_alloc: - * @x contains the xfrm_state being added to the Security Association - * Database by the XFRM system. - * @sec_ctx contains the security context information being provided by - * the user-level SA generation program (e.g., setkey or racoon). - * Allocate a security structure to the x->security field; the security - * field is initialized to NULL when the xfrm_state is allocated. Set the - * context to correspond to sec_ctx. Return 0 if operation was successful - * (memory to allocate, legal context). - * @xfrm_state_alloc_acquire: - * @x contains the xfrm_state being added to the Security Association - * Database by the XFRM system. - * @polsec contains the policy's security context. - * @secid contains the secid from which to take the mls portion of the - * context. - * Allocate a security structure to the x->security field; the security - * field is initialized to NULL when the xfrm_state is allocated. Set the - * context to correspond to secid. Return 0 if operation was successful - * (memory to allocate, legal context). - * @xfrm_state_free_security: - * @x contains the xfrm_state. - * Deallocate x->security. - * @xfrm_state_delete_security: - * @x contains the xfrm_state. - * Authorize deletion of x->security. - * Return 0 if permission is granted. - * @xfrm_policy_lookup: - * @ctx contains the xfrm_sec_ctx for which the access control is being - * checked. - * @fl_secid contains the flow security label that is used to authorize - * access to the policy xp. - * @dir contains the direction of the flow (input or output). - * Check permission when a flow selects a xfrm_policy for processing - * XFRMs on a packet. The hook is called when selecting either a - * per-socket policy or a generic xfrm policy. - * Return 0 if permission is granted, -ESRCH otherwise, or -errno - * on other errors. - * @xfrm_state_pol_flow_match: - * @x contains the state to match. - * @xp contains the policy to check for a match. - * @flic contains the flowi_common struct to check for a match. - * Return 1 if there is a match. - * @xfrm_decode_session: - * @skb points to skb to decode. - * @secid points to the flow key secid to set. - * @ckall says if all xfrms used should be checked for same secid. - * Return 0 if ckall is zero or all xfrms used have the same secid. - * * Security hooks affecting all Key Management operations * * @key_alloc: diff --git a/security/security.c b/security/security.c index 6e786e277a7f..d3880096922e 100644 --- a/security/security.c +++ b/security/security.c @@ -4269,6 +4269,17 @@ EXPORT_SYMBOL(security_ib_free_security); #ifdef CONFIG_SECURITY_NETWORK_XFRM +/** + * security_xfrm_policy_alloc() - Allocate a xfrm policy LSM blob + * @ctxp: xfrm security context being added to the SPD + * @sec_ctx: security label provided by userspace + * @gfp: gfp flags + * + * Allocate a security structure to the xp->security field; the security field + * is initialized to NULL when the xfrm_policy is allocated. + * + * Return: Return 0 if operation was successful. + */ int security_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, struct xfrm_user_sec_ctx *sec_ctx, gfp_t gfp) @@ -4277,23 +4288,58 @@ int security_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp, } EXPORT_SYMBOL(security_xfrm_policy_alloc); +/** + * security_xfrm_policy_clone() - Clone xfrm policy LSM state + * @old_ctx: xfrm security context + * @new_ctxp: target xfrm security context + * + * Allocate a security structure in new_ctxp that contains the information from + * the old_ctx structure. + * + * Return: Return 0 if operation was successful. + */ int security_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx, struct xfrm_sec_ctx **new_ctxp) { return call_int_hook(xfrm_policy_clone_security, 0, old_ctx, new_ctxp); } +/** + * security_xfrm_policy_free() - Free a xfrm security context + * @ctx: xfrm security context + * + * Free LSM resources associated with @ctx. + */ void security_xfrm_policy_free(struct xfrm_sec_ctx *ctx) { call_void_hook(xfrm_policy_free_security, ctx); } EXPORT_SYMBOL(security_xfrm_policy_free); +/** + * security_xfrm_policy_delete() - Check if deleting a xfrm policy is allowed + * @ctx: xfrm security context + * + * Authorize deletion of a SPD entry. + * + * Return: Returns 0 if permission is granted. + */ int security_xfrm_policy_delete(struct xfrm_sec_ctx *ctx) { return call_int_hook(xfrm_policy_delete_security, 0, ctx); } +/** + * security_xfrm_state_alloc() - Allocate a xfrm state LSM blob + * @x: xfrm state being added to the SAD + * @sec_ctx: security label provided by userspace + * + * Allocate a security structure to the @x->security field; the security field + * is initialized to NULL when the xfrm_state is allocated. Set the context to + * correspond to @sec_ctx. + * + * Return: Return 0 if operation was successful. + */ int security_xfrm_state_alloc(struct xfrm_state *x, struct xfrm_user_sec_ctx *sec_ctx) { @@ -4301,28 +4347,76 @@ int security_xfrm_state_alloc(struct xfrm_state *x, } EXPORT_SYMBOL(security_xfrm_state_alloc); +/** + * security_xfrm_state_alloc_acquire() - Allocate a xfrm state LSM blob + * @x: xfrm state being added to the SAD + * @polsec: associated policy's security context + * @secid: secid from the flow + * + * Allocate a security structure to the x->security field; the security field + * is initialized to NULL when the xfrm_state is allocated. Set the context to + * correspond to secid. + * + * Return: Returns 0 if operation was successful. + */ int security_xfrm_state_alloc_acquire(struct xfrm_state *x, struct xfrm_sec_ctx *polsec, u32 secid) { return call_int_hook(xfrm_state_alloc_acquire, 0, x, polsec, secid); } +/** + * security_xfrm_state_delete() - Check if deleting a xfrm state is allowed + * @x: xfrm state + * + * Authorize deletion of x->security. + * + * Return: Returns 0 if permission is granted. + */ int security_xfrm_state_delete(struct xfrm_state *x) { return call_int_hook(xfrm_state_delete_security, 0, x); } EXPORT_SYMBOL(security_xfrm_state_delete); +/** + * security_xfrm_state_free() - Free a xfrm state + * @x: xfrm state + * + * Deallocate x->security. + */ void security_xfrm_state_free(struct xfrm_state *x) { call_void_hook(xfrm_state_free_security, x); } +/** + * security_xfrm_policy_lookup() - Check if using a xfrm policy is allowed + * @ctx: target xfrm security context + * @fl_secid: flow secid used to authorize access + * + * Check permission when a flow selects a xfrm_policy for processing XFRMs on a + * packet. The hook is called when selecting either a per-socket policy or a + * generic xfrm policy. + * + * Return: Return 0 if permission is granted, -ESRCH otherwise, or -errno on + * other errors. + */ int security_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid) { return call_int_hook(xfrm_policy_lookup, 0, ctx, fl_secid); } +/** + * security_xfrm_state_pol_flow_match() - Check for a xfrm match + * @x: xfrm state to match + * @xp xfrm policy to check for a match + * @flic: flow to check for a match. + * + * Check @xp and @flic for a match with @x. + * + * Return: Returns 1 if there is a match. + */ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *xp, const struct flowi_common *flic) @@ -4347,6 +4441,15 @@ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, return rc; } +/** + * security_xfrm_decode_session() - Determine the xfrm secid for a packet + * @skb: xfrm packet + * @secid: secid + * + * Decode the packet in @skb and return the security label in @secid. + * + * Return: Return 0 if all xfrms used have the same secid. + */ int security_xfrm_decode_session(struct sk_buff *skb, u32 *secid) { return call_int_hook(xfrm_decode_session, 0, skb, secid, 1); From ecc419a4453530c410c7031bc69ef34782b1c8ff Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 15 Feb 2023 21:46:31 -0500 Subject: [PATCH 14/32] lsm: move the key hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 32 ------------------------------- security/security.c | 40 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 32 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 9c5254e4e9d1..2cfa56e3abc3 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,38 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks affecting all Key Management operations - * - * @key_alloc: - * Permit allocation of a key and assign security data. Note that key does - * not have a serial number assigned at this point. - * @key points to the key. - * @flags is the allocation flags. - * Return 0 if permission is granted, -ve error otherwise. - * @key_free: - * Notification of destruction; free security data. - * @key points to the key. - * No return value. - * @key_permission: - * See whether a specific operational right is granted to a process on a - * key. - * @key_ref refers to the key (key pointer + possession attribute bit). - * @cred points to the credentials to provide the context against which to - * evaluate the security data on the key. - * @perm describes the combination of permissions required of this key. - * Return 0 if permission is granted, -ve error otherwise. - * @key_getsecurity: - * Get a textual representation of the security context attached to a key - * for the purposes of honouring KEYCTL_GETSECURITY. This function - * allocates the storage for the NUL-terminated string and the caller - * should free it. - * @key points to the key to be queried. - * @_buffer points to a pointer that should be set to point to the - * resulting string (if no label or an error occurs). - * Return the length of the string (including terminating NUL) or -ve if - * an error. - * May also return 0 (and a NULL buffer pointer) if there is no label. - * * Security hooks affecting all System V IPC operations. * * @ipc_permission: diff --git a/security/security.c b/security/security.c index d3880096922e..bde8d24af6ac 100644 --- a/security/security.c +++ b/security/security.c @@ -4468,23 +4468,63 @@ EXPORT_SYMBOL(security_skb_classify_flow); #ifdef CONFIG_KEYS +/** + * security_key_alloc() - Allocate and initialize a kernel key LSM blob + * @key: key + * @cred: credentials + * @flags: allocation flags + * + * Permit allocation of a key and assign security data. Note that key does not + * have a serial number assigned at this point. + * + * Return: Return 0 if permission is granted, -ve error otherwise. + */ int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { return call_int_hook(key_alloc, 0, key, cred, flags); } +/** + * security_key_free() - Free a kernel key LSM blob + * @key: key + * + * Notification of destruction; free security data. + */ void security_key_free(struct key *key) { call_void_hook(key_free, key); } +/** + * security_key_permission() - Check if a kernel key operation is allowed + * @key_ref: key reference + * @cred: credentials of actor requesting access + * @need_perm: requested permissions + * + * See whether a specific operational right is granted to a process on a key. + * + * Return: Return 0 if permission is granted, -ve error otherwise. + */ int security_key_permission(key_ref_t key_ref, const struct cred *cred, enum key_need_perm need_perm) { return call_int_hook(key_permission, 0, key_ref, cred, need_perm); } +/** + * security_key_getsecurity() - Get the key's security label + * @key: key + * @buffer: security label buffer + * + * Get a textual representation of the security context attached to a key for + * the purposes of honouring KEYCTL_GETSECURITY. This function allocates the + * storage for the NUL-terminated string and the caller should free it. + * + * Return: Returns the length of @buffer (including terminating NUL) or -ve if + * an error occurs. May also return 0 (and a NULL buffer pointer) if + * there is no security label assigned to the key. + */ int security_key_getsecurity(struct key *key, char **_buffer) { *_buffer = NULL; From 43fad282187695e25c51425ee9f5f9f08fe5e15d Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 16 Feb 2023 11:53:49 -0500 Subject: [PATCH 15/32] lsm: move the sysv hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 141 ---------------------------- security/security.c | 191 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 191 insertions(+), 141 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 2cfa56e3abc3..f6679fead627 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,147 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks affecting all System V IPC operations. - * - * @ipc_permission: - * Check permissions for access to IPC - * @ipcp contains the kernel IPC permission structure. - * @flag contains the desired (requested) permission set. - * Return 0 if permission is granted. - * @ipc_getsecid: - * Get the secid associated with the ipc object. - * @ipcp contains the kernel IPC permission structure. - * @secid contains a pointer to the location where result will be saved. - * In case of failure, @secid will be set to zero. - * - * Security hooks for individual messages held in System V IPC message queues - * - * @msg_msg_alloc_security: - * Allocate and attach a security structure to the msg->security field. - * The security field is initialized to NULL when the structure is first - * created. - * @msg contains the message structure to be modified. - * Return 0 if operation was successful and permission is granted. - * @msg_msg_free_security: - * Deallocate the security structure for this message. - * @msg contains the message structure to be modified. - * - * Security hooks for System V IPC Message Queues - * - * @msg_queue_alloc_security: - * Allocate and attach a security structure to the - * @perm->security field. The security field is initialized to - * NULL when the structure is first created. - * @perm contains the IPC permissions of the message queue. - * Return 0 if operation was successful and permission is granted. - * @msg_queue_free_security: - * Deallocate security field @perm->security for the message queue. - * @perm contains the IPC permissions of the message queue. - * @msg_queue_associate: - * Check permission when a message queue is requested through the - * msgget system call. This hook is only called when returning the - * message queue identifier for an existing message queue, not when a - * new message queue is created. - * @perm contains the IPC permissions of the message queue. - * @msqflg contains the operation control flags. - * Return 0 if permission is granted. - * @msg_queue_msgctl: - * Check permission when a message control operation specified by @cmd - * is to be performed on the message queue with permissions @perm. - * The @perm may be NULL, e.g. for IPC_INFO or MSG_INFO. - * @perm contains the IPC permissions of the msg queue. May be NULL. - * @cmd contains the operation to be performed. - * Return 0 if permission is granted. - * @msg_queue_msgsnd: - * Check permission before a message, @msg, is enqueued on the message - * queue with permissions @perm. - * @perm contains the IPC permissions of the message queue. - * @msg contains the message to be enqueued. - * @msqflg contains operational flags. - * Return 0 if permission is granted. - * @msg_queue_msgrcv: - * Check permission before a message, @msg, is removed from the message - * queue. The @target task structure contains a pointer to the - * process that will be receiving the message (not equal to the current - * process when inline receives are being performed). - * @perm contains the IPC permissions of the message queue. - * @msg contains the message destination. - * @target contains the task structure for recipient process. - * @type contains the type of message requested. - * @mode contains the operational flags. - * Return 0 if permission is granted. - * - * Security hooks for System V Shared Memory Segments - * - * @shm_alloc_security: - * Allocate and attach a security structure to the @perm->security - * field. The security field is initialized to NULL when the structure is - * first created. - * @perm contains the IPC permissions of the shared memory structure. - * Return 0 if operation was successful and permission is granted. - * @shm_free_security: - * Deallocate the security structure @perm->security for the memory segment. - * @perm contains the IPC permissions of the shared memory structure. - * @shm_associate: - * Check permission when a shared memory region is requested through the - * shmget system call. This hook is only called when returning the shared - * memory region identifier for an existing region, not when a new shared - * memory region is created. - * @perm contains the IPC permissions of the shared memory structure. - * @shmflg contains the operation control flags. - * Return 0 if permission is granted. - * @shm_shmctl: - * Check permission when a shared memory control operation specified by - * @cmd is to be performed on the shared memory region with permissions @perm. - * The @perm may be NULL, e.g. for IPC_INFO or SHM_INFO. - * @perm contains the IPC permissions of the shared memory structure. - * @cmd contains the operation to be performed. - * Return 0 if permission is granted. - * @shm_shmat: - * Check permissions prior to allowing the shmat system call to attach the - * shared memory segment with permissions @perm to the data segment of the - * calling process. The attaching address is specified by @shmaddr. - * @perm contains the IPC permissions of the shared memory structure. - * @shmaddr contains the address to attach memory region to. - * @shmflg contains the operational flags. - * Return 0 if permission is granted. - * - * Security hooks for System V Semaphores - * - * @sem_alloc_security: - * Allocate and attach a security structure to the @perm->security - * field. The security field is initialized to NULL when the structure is - * first created. - * @perm contains the IPC permissions of the semaphore. - * Return 0 if operation was successful and permission is granted. - * @sem_free_security: - * Deallocate security structure @perm->security for the semaphore. - * @perm contains the IPC permissions of the semaphore. - * @sem_associate: - * Check permission when a semaphore is requested through the semget - * system call. This hook is only called when returning the semaphore - * identifier for an existing semaphore, not when a new one must be - * created. - * @perm contains the IPC permissions of the semaphore. - * @semflg contains the operation control flags. - * Return 0 if permission is granted. - * @sem_semctl: - * Check permission when a semaphore operation specified by @cmd is to be - * performed on the semaphore. The @perm may be NULL, e.g. for - * IPC_INFO or SEM_INFO. - * @perm contains the IPC permissions of the semaphore. May be NULL. - * @cmd contains the operation to be performed. - * Return 0 if permission is granted. - * @sem_semop: - * Check permissions before performing operations on members of the - * semaphore set. If the @alter flag is nonzero, the semaphore set - * may be modified. - * @perm contains the IPC permissions of the semaphore. - * @sops contains the operations to perform. - * @nsops contains the number of operations to perform. - * @alter contains the flag indicating whether changes are to be made. - * Return 0 if permission is granted. - * * @binder_set_context_mgr: * Check whether @mgr is allowed to be the binder context manager. * @mgr contains the struct cred for the current binder process. diff --git a/security/security.c b/security/security.c index bde8d24af6ac..83443984b11a 100644 --- a/security/security.c +++ b/security/security.c @@ -3254,17 +3254,43 @@ int security_create_user_ns(const struct cred *cred) return call_int_hook(userns_create, 0, cred); } +/** + * security_ipc_permission() - Check if sysv ipc access is allowed + * @ipcp: ipc permission structure + * @flags: requested permissions + * + * Check permissions for access to IPC. + * + * Return: Returns 0 if permission is granted. + */ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag) { return call_int_hook(ipc_permission, 0, ipcp, flag); } +/** + * security_ipc_getsecid() - Get the sysv ipc object's secid + * @ipcp: ipc permission structure + * @secid: secid pointer + * + * Get the secid associated with the ipc object. In case of failure, @secid + * will be set to zero. + */ void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) { *secid = 0; call_void_hook(ipc_getsecid, ipcp, secid); } +/** + * security_msg_msg_alloc() - Allocate a sysv ipc message LSM blob + * @msg: message structure + * + * Allocate and attach a security structure to the msg->security field. The + * security field is initialized to NULL when the structure is first created. + * + * Return: Return 0 if operation was successful and permission is granted. + */ int security_msg_msg_alloc(struct msg_msg *msg) { int rc = lsm_msg_msg_alloc(msg); @@ -3277,6 +3303,12 @@ int security_msg_msg_alloc(struct msg_msg *msg) return rc; } +/** + * security_msg_msg_free() - Free a sysv ipc message LSM blob + * @msg: message structure + * + * Deallocate the security structure for this message. + */ void security_msg_msg_free(struct msg_msg *msg) { call_void_hook(msg_msg_free_security, msg); @@ -3284,6 +3316,15 @@ void security_msg_msg_free(struct msg_msg *msg) msg->security = NULL; } +/** + * security_msg_queue_alloc() - Allocate a sysv ipc msg queue LSM blob + * @msq: sysv ipc permission structure + * + * Allocate and attach a security structure to @msg. The security field is + * initialized to NULL when the structure is first created. + * + * Return: Returns 0 if operation was successful and permission is granted. + */ int security_msg_queue_alloc(struct kern_ipc_perm *msq) { int rc = lsm_ipc_alloc(msq); @@ -3296,6 +3337,12 @@ int security_msg_queue_alloc(struct kern_ipc_perm *msq) return rc; } +/** + * security_msg_queue_free() - Free a sysv ipc msg queue LSM blob + * @msq: sysv ipc permission structure + * + * Deallocate security field @perm->security for the message queue. + */ void security_msg_queue_free(struct kern_ipc_perm *msq) { call_void_hook(msg_queue_free_security, msq); @@ -3303,28 +3350,84 @@ void security_msg_queue_free(struct kern_ipc_perm *msq) msq->security = NULL; } +/** + * security_msg_queue_associate() - Check if a msg queue operation is allowed + * @msq: sysv ipc permission structure + * @msqflg: operation flags + * + * Check permission when a message queue is requested through the msgget system + * call. This hook is only called when returning the message queue identifier + * for an existing message queue, not when a new message queue is created. + * + * Return: Return 0 if permission is granted. + */ int security_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg) { return call_int_hook(msg_queue_associate, 0, msq, msqflg); } +/** + * security_msg_queue_msgctl() - Check if a msg queue operation is allowed + * @msq: sysv ipc permission structure + * @cmd: operation + * + * Check permission when a message control operation specified by @cmd is to be + * performed on the message queue with permissions. + * + * Return: Returns 0 if permission is granted. + */ int security_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd) { return call_int_hook(msg_queue_msgctl, 0, msq, cmd); } +/** + * security_msg_queue_msgsnd() - Check if sending a sysv ipc message is allowed + * @msq: sysv ipc permission structure + * @msg: message + * @msqflg: operation flags + * + * Check permission before a message, @msg, is enqueued on the message queue + * with permissions specified in @msq. + * + * Return: Returns 0 if permission is granted. + */ int security_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg) { return call_int_hook(msg_queue_msgsnd, 0, msq, msg, msqflg); } +/** + * security_msg_queue_msgrcv() - Check if receiving a sysv ipc msg is allowed + * @msq: sysv ipc permission structure + * @msg: message + * @target: target task + * @type: type of message requested + * @mode: operation flags + * + * Check permission before a message, @msg, is removed from the message queue. + * The @target task structure contains a pointer to the process that will be + * receiving the message (not equal to the current process when inline receives + * are being performed). + * + * Return: Returns 0 if permission is granted. + */ int security_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg, struct task_struct *target, long type, int mode) { return call_int_hook(msg_queue_msgrcv, 0, msq, msg, target, type, mode); } +/** + * security_shm_alloc() - Allocate a sysv shm LSM blob + * @shp: sysv ipc permission structure + * + * Allocate and attach a security structure to the @shp security field. The + * security field is initialized to NULL when the structure is first created. + * + * Return: Returns 0 if operation was successful and permission is granted. + */ int security_shm_alloc(struct kern_ipc_perm *shp) { int rc = lsm_ipc_alloc(shp); @@ -3337,6 +3440,12 @@ int security_shm_alloc(struct kern_ipc_perm *shp) return rc; } +/** + * security_shm_free() - Free a sysv shm LSM blob + * @shp: sysv ipc permission structure + * + * Deallocate the security structure @perm->security for the memory segment. + */ void security_shm_free(struct kern_ipc_perm *shp) { call_void_hook(shm_free_security, shp); @@ -3344,21 +3453,64 @@ void security_shm_free(struct kern_ipc_perm *shp) shp->security = NULL; } +/** + * security_shm_associate() - Check if a sysv shm operation is allowed + * @shp: sysv ipc permission structure + * @shmflg: operation flags + * + * Check permission when a shared memory region is requested through the shmget + * system call. This hook is only called when returning the shared memory + * region identifier for an existing region, not when a new shared memory + * region is created. + * + * Return: Returns 0 if permission is granted. + */ int security_shm_associate(struct kern_ipc_perm *shp, int shmflg) { return call_int_hook(shm_associate, 0, shp, shmflg); } +/** + * security_shm_shmctl() - Check if a sysv shm operation is allowed + * @shp: sysv ipc permission structure + * @cmd: operation + * + * Check permission when a shared memory control operation specified by @cmd is + * to be performed on the shared memory region with permissions in @shp. + * + * Return: Return 0 if permission is granted. + */ int security_shm_shmctl(struct kern_ipc_perm *shp, int cmd) { return call_int_hook(shm_shmctl, 0, shp, cmd); } +/** + * security_shm_shmat() - Check if a sysv shm attach operation is allowed + * @shp: sysv ipc permission structure + * @shmaddr: address of memory region to attach + * @shmflg: operation flags + * + * Check permissions prior to allowing the shmat system call to attach the + * shared memory segment with permissions @shp to the data segment of the + * calling process. The attaching address is specified by @shmaddr. + * + * Return: Returns 0 if permission is granted. + */ int security_shm_shmat(struct kern_ipc_perm *shp, char __user *shmaddr, int shmflg) { return call_int_hook(shm_shmat, 0, shp, shmaddr, shmflg); } +/** + * security_sem_alloc() - Allocate a sysv semaphore LSM blob + * @sma: sysv ipc permission structure + * + * Allocate and attach a security structure to the @sma security field. The + * security field is initialized to NULL when the structure is first created. + * + * Return: Returns 0 if operation was successful and permission is granted. + */ int security_sem_alloc(struct kern_ipc_perm *sma) { int rc = lsm_ipc_alloc(sma); @@ -3371,6 +3523,12 @@ int security_sem_alloc(struct kern_ipc_perm *sma) return rc; } +/** + * security_sem_free() - Free a sysv semaphore LSM blob + * @sma: sysv ipc permission structure + * + * Deallocate security structure @sma->security for the semaphore. + */ void security_sem_free(struct kern_ipc_perm *sma) { call_void_hook(sem_free_security, sma); @@ -3378,16 +3536,49 @@ void security_sem_free(struct kern_ipc_perm *sma) sma->security = NULL; } +/** + * security_sem_associate() - Check if a sysv semaphore operation is allowed + * @sma: sysv ipc permission structure + * @semflg: operation flags + * + * Check permission when a semaphore is requested through the semget system + * call. This hook is only called when returning the semaphore identifier for + * an existing semaphore, not when a new one must be created. + * + * Return: Returns 0 if permission is granted. + */ int security_sem_associate(struct kern_ipc_perm *sma, int semflg) { return call_int_hook(sem_associate, 0, sma, semflg); } +/** + * security_sem_ctl() - Check if a sysv semaphore operation is allowed + * @sma: sysv ipc permission structure + * @cmd: operation + * + * Check permission when a semaphore operation specified by @cmd is to be + * performed on the semaphore. + * + * Return: Returns 0 if permission is granted. + */ int security_sem_semctl(struct kern_ipc_perm *sma, int cmd) { return call_int_hook(sem_semctl, 0, sma, cmd); } +/** + * security_sem_semop() - Check if a sysv semaphore operation is allowed + * @sma: sysv ipc permission structure + * @sops: operations to perform + * @nsops: number of operations + * @alter: flag indicating changes will be made + * + * Check permissions before performing operations on members of the semaphore + * set. If the @alter flag is nonzero, the semaphore set may be modified. + * + * Return: Returns 0 if permission is granted. + */ int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops, unsigned nsops, int alter) { From 1427ddbe5cc1a3d4ac068cea78638baf95f16c18 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 16 Feb 2023 16:39:08 -0500 Subject: [PATCH 16/32] lsm: move the binder hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 22 ---------------------- security/security.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+), 22 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index f6679fead627..0a5b3b46fc2b 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,28 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * @binder_set_context_mgr: - * Check whether @mgr is allowed to be the binder context manager. - * @mgr contains the struct cred for the current binder process. - * Return 0 if permission is granted. - * @binder_transaction: - * Check whether @from is allowed to invoke a binder transaction call - * to @to. - * @from contains the struct cred for the sending process. - * @to contains the struct cred for the receiving process. - * Return 0 if permission is granted. - * @binder_transfer_binder: - * Check whether @from is allowed to transfer a binder reference to @to. - * @from contains the struct cred for the sending process. - * @to contains the struct cred for the receiving process. - * Return 0 if permission is granted. - * @binder_transfer_file: - * Check whether @from is allowed to transfer @file to @to. - * @from contains the struct cred for the sending process. - * @file contains the struct file being transferred. - * @to contains the struct cred for the receiving process. - * Return 0 if permission is granted. - * * @ptrace_access_check: * Check permission before allowing the current process to trace the * @child process. diff --git a/security/security.c b/security/security.c index 83443984b11a..b21154ed152f 100644 --- a/security/security.c +++ b/security/security.c @@ -779,23 +779,59 @@ static int lsm_superblock_alloc(struct super_block *sb) /* Security operations */ +/** + * security_binder_set_context_mgr() - Check if becoming binder ctx mgr is ok + * @mgr: task credentials of current binder process + * + * Check whether @mgr is allowed to be the binder context manager. + * + * Return: Return 0 if permission is granted. + */ int security_binder_set_context_mgr(const struct cred *mgr) { return call_int_hook(binder_set_context_mgr, 0, mgr); } +/** + * security_binder_transaction() - Check if a binder transaction is allowed + * @from: sending process + * @to: receiving process + * + * Check whether @from is allowed to invoke a binder transaction call to @to. + * + * Return: Returns 0 if permission is granted. + */ int security_binder_transaction(const struct cred *from, const struct cred *to) { return call_int_hook(binder_transaction, 0, from, to); } +/** + * security_binder_transfer_binder() - Check if a binder transfer is allowed + * @from: sending process + * @to: receiving process + * + * Check whether @from is allowed to transfer a binder reference to @to. + * + * Return: Returns 0 if permission is granted. + */ int security_binder_transfer_binder(const struct cred *from, const struct cred *to) { return call_int_hook(binder_transfer_binder, 0, from, to); } +/** + * security_binder_transfer_file() - Check if a binder file xfer is allowed + * @from: sending process + * @to: receiving process + * @file: file being transferred + * + * Check whether @from is allowed to transfer @file to @to. + * + * Return: Returns 0 if permission is granted. + */ int security_binder_transfer_file(const struct cred *from, const struct cred *to, struct file *file) { From b14faf9c94a66ef398c2c3fa6e141814f04e274e Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 16 Feb 2023 17:00:01 -0500 Subject: [PATCH 17/32] lsm: move the audit hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 32 ------------------------------ security/security.c | 41 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+), 32 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 0a5b3b46fc2b..e36387f88083 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -135,38 +135,6 @@ * @secdata contains the security context. * @seclen contains the length of the security context. * - * Security hooks for Audit - * - * @audit_rule_init: - * Allocate and initialize an LSM audit rule structure. - * @field contains the required Audit action. - * Fields flags are defined in - * @op contains the operator the rule uses. - * @rulestr contains the context where the rule will be applied to. - * @lsmrule contains a pointer to receive the result. - * Return 0 if @lsmrule has been successfully set, - * -EINVAL in case of an invalid rule. - * - * @audit_rule_known: - * Specifies whether given @krule contains any fields related to - * current LSM. - * @krule contains the audit rule of interest. - * Return 1 in case of relation found, 0 otherwise. - * - * @audit_rule_match: - * Determine if given @secid matches a rule previously approved - * by @audit_rule_known. - * @secid contains the security id in question. - * @field contains the field which relates to current LSM. - * @op contains the operator that will be used for matching. - * @lrule points to the audit rule that will be checked against. - * Return 1 if secid matches the rule, 0 if it does not, -ERRNO on failure. - * - * @audit_rule_free: - * Deallocate the LSM audit rule structure previously allocated by - * audit_rule_init. - * @lsmrule contains the allocated rule. - * * @inode_invalidate_secctx: * Notify the security module that it must revalidate the security context * of an inode. diff --git a/security/security.c b/security/security.c index b21154ed152f..80c05c28b7ff 100644 --- a/security/security.c +++ b/security/security.c @@ -4762,21 +4762,62 @@ int security_key_getsecurity(struct key *key, char **_buffer) #ifdef CONFIG_AUDIT +/** + * security_audit_rule_init() - Allocate and init an LSM audit rule struct + * @field: audit action + * @op: rule operator + * @rulestr: rule context + * @lsmrule: receive buffer for audit rule struct + * + * Allocate and initialize an LSM audit rule structure. + * + * Return: Return 0 if @lsmrule has been successfully set, -EINVAL in case of + * an invalid rule. + */ int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule) { return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule); } +/** + * security_audit_rule_known() - Check if an audit rule contains LSM fields + * @krule: audit rule + * + * Specifies whether given @krule contains any fields related to the current + * LSM. + * + * Return: Returns 1 in case of relation found, 0 otherwise. + */ int security_audit_rule_known(struct audit_krule *krule) { return call_int_hook(audit_rule_known, 0, krule); } +/** + * security_audit_rule_free() - Free an LSM audit rule struct + * @lsmrule: audit rule struct + * + * Deallocate the LSM audit rule structure previously allocated by + * audit_rule_init(). + */ void security_audit_rule_free(void *lsmrule) { call_void_hook(audit_rule_free, lsmrule); } +/** + * security_audit_rule_match() - Check if a label matches an audit rule + * @secid: security label + * @field: LSM audit field + * @op: matching operator + * @lsmrule: audit rule + * + * Determine if given @secid matches a rule previously approved by + * security_audit_rule_known(). + * + * Return: Returns 1 if secid matches the rule, 0 if it does not, -ERRNO on + * failure. + */ int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule) { return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule); From 55e853201a9e0383c9f6d5d800155e334685cd7e Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 16 Feb 2023 17:13:40 -0500 Subject: [PATCH 18/32] lsm: move the bpf hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 36 ---------------------- security/security.c | 65 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+), 36 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index e36387f88083..601d1ecdae0f 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -190,42 +190,6 @@ * @key: The key to watch. * Return 0 if permission is granted. * - * Security hooks for using the eBPF maps and programs functionalities through - * eBPF syscalls. - * - * @bpf: - * Do a initial check for all bpf syscalls after the attribute is copied - * into the kernel. The actual security module can implement their own - * rules to check the specific cmd they need. - * Return 0 if permission is granted. - * - * @bpf_map: - * Do a check when the kernel generate and return a file descriptor for - * eBPF maps. - * @map: bpf map that we want to access. - * @mask: the access flags. - * Return 0 if permission is granted. - * - * @bpf_prog: - * Do a check when the kernel generate and return a file descriptor for - * eBPF programs. - * @prog: bpf prog that userspace want to use. - * Return 0 if permission is granted. - * - * @bpf_map_alloc_security: - * Initialize the security field inside bpf map. - * Return 0 on success, error on failure. - * - * @bpf_map_free_security: - * Clean up the security information stored inside bpf map. - * - * @bpf_prog_alloc_security: - * Initialize the security field inside bpf program. - * Return 0 on success, error on failure. - * - * @bpf_prog_free_security: - * Clean up the security information stored inside bpf prog. - * * @locked_down: * Determine whether a kernel feature that potentially enables arbitrary * code execution in kernel space should be permitted. diff --git a/security/security.c b/security/security.c index 80c05c28b7ff..4037af6b5196 100644 --- a/security/security.c +++ b/security/security.c @@ -4825,30 +4825,95 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule) #endif /* CONFIG_AUDIT */ #ifdef CONFIG_BPF_SYSCALL +/** + * security_bpf() - Check if the bpf syscall operation is allowed + * @cmd: command + * @attr: bpf attribute + * @size: size + * + * Do a initial check for all bpf syscalls after the attribute is copied into + * the kernel. The actual security module can implement their own rules to + * check the specific cmd they need. + * + * Return: Returns 0 if permission is granted. + */ int security_bpf(int cmd, union bpf_attr *attr, unsigned int size) { return call_int_hook(bpf, 0, cmd, attr, size); } + +/** + * security_bpf_map() - Check if access to a bpf map is allowed + * @map: bpf map + * @fmode: mode + * + * Do a check when the kernel generates and returns a file descriptor for eBPF + * maps. + * + * Return: Returns 0 if permission is granted. + */ int security_bpf_map(struct bpf_map *map, fmode_t fmode) { return call_int_hook(bpf_map, 0, map, fmode); } + +/** + * security_bpf_prog() - Check if access to a bpf program is allowed + * @prog: bpf program + * + * Do a check when the kernel generates and returns a file descriptor for eBPF + * programs. + * + * Return: Returns 0 if permission is granted. + */ int security_bpf_prog(struct bpf_prog *prog) { return call_int_hook(bpf_prog, 0, prog); } + +/** + * security_bpf_map_alloc() - Allocate a bpf map LSM blob + * @map: bpf map + * + * Initialize the security field inside bpf map. + * + * Return: Returns 0 on success, error on failure. + */ int security_bpf_map_alloc(struct bpf_map *map) { return call_int_hook(bpf_map_alloc_security, 0, map); } + +/** + * security_bpf_prog_alloc() - Allocate a bpf program LSM blob + * @aux: bpf program aux info struct + * + * Initialize the security field inside bpf program. + * + * Return: Returns 0 on success, error on failure. + */ int security_bpf_prog_alloc(struct bpf_prog_aux *aux) { return call_int_hook(bpf_prog_alloc_security, 0, aux); } + +/** + * security_bpf_map_free() - Free a bpf map's LSM blob + * @map: bpf map + * + * Clean up the security information stored inside bpf map. + */ void security_bpf_map_free(struct bpf_map *map) { call_void_hook(bpf_map_free_security, map); } + +/** + * security_bpf_prog_free() - Free a bpf program's LSM blob + * @aux: bpf program aux info struct + * + * Clean up the security information stored inside bpf prog. + */ void security_bpf_prog_free(struct bpf_prog_aux *aux) { call_void_hook(bpf_prog_free_security, aux); From 452b670c7222c7bf11b45b13f5a736f96d0be1e3 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 16 Feb 2023 17:22:36 -0500 Subject: [PATCH 19/32] lsm: move the perf hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 17 ----------------- security/security.c | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 17 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 601d1ecdae0f..3d8d430e271a 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -196,23 +196,6 @@ * @what: kernel feature being accessed. * Return 0 if permission is granted. * - * Security hooks for perf events - * - * @perf_event_open: - * Check whether the @type of perf_event_open syscall is allowed. - * Return 0 if permission is granted. - * @perf_event_alloc: - * Allocate and save perf_event security info. - * Return 0 on success, error on failure. - * @perf_event_free: - * Release (free) perf_event security info. - * @perf_event_read: - * Read perf_event security info if allowed. - * Return 0 if permission is granted. - * @perf_event_write: - * Write perf_event security info if allowed. - * Return 0 if permission is granted. - * * Security hooks for io_uring * * @uring_override_creds: diff --git a/security/security.c b/security/security.c index 4037af6b5196..47506ae1b187 100644 --- a/security/security.c +++ b/security/security.c @@ -4927,26 +4927,65 @@ int security_locked_down(enum lockdown_reason what) EXPORT_SYMBOL(security_locked_down); #ifdef CONFIG_PERF_EVENTS +/** + * security_perf_event_open() - Check if a perf event open is allowed + * @attr: perf event attribute + * @type: type of event + * + * Check whether the @type of perf_event_open syscall is allowed. + * + * Return: Returns 0 if permission is granted. + */ int security_perf_event_open(struct perf_event_attr *attr, int type) { return call_int_hook(perf_event_open, 0, attr, type); } +/** + * security_perf_event_alloc() - Allocate a perf event LSM blob + * @event: perf event + * + * Allocate and save perf_event security info. + * + * Return: Returns 0 on success, error on failure. + */ int security_perf_event_alloc(struct perf_event *event) { return call_int_hook(perf_event_alloc, 0, event); } +/** + * security_perf_event_free() - Free a perf event LSM blob + * @event: perf event + * + * Release (free) perf_event security info. + */ void security_perf_event_free(struct perf_event *event) { call_void_hook(perf_event_free, event); } +/** + * security_perf_event_read() - Check if reading a perf event label is allowed + * @event: perf event + * + * Read perf_event security info if allowed. + * + * Return: Returns 0 if permission is granted. + */ int security_perf_event_read(struct perf_event *event) { return call_int_hook(perf_event_read, 0, event); } +/** + * security_perf_event_write() - Check if writing a perf event label is allowed + * @event: perf event + * + * Write perf_event security info if allowed. + * + * Return: Returns 0 if permission is granted. + */ int security_perf_event_write(struct perf_event *event) { return call_int_hook(perf_event_write, 0, event); From 1cd2aca64a5dc4edb65539dc26f24e162ab0e11c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 16 Feb 2023 17:28:31 -0500 Subject: [PATCH 20/32] lsm: move the io_uring hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 17 ----------------- security/security.c | 26 ++++++++++++++++++++++++++ 2 files changed, 26 insertions(+), 17 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 3d8d430e271a..8e006df1db56 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -196,23 +196,6 @@ * @what: kernel feature being accessed. * Return 0 if permission is granted. * - * Security hooks for io_uring - * - * @uring_override_creds: - * Check if the current task, executing an io_uring operation, is allowed - * to override it's credentials with @new. - * @new: the new creds to use. - * Return 0 if permission is granted. - * - * @uring_sqpoll: - * Check whether the current task is allowed to spawn a io_uring polling - * thread (IORING_SETUP_SQPOLL). - * Return 0 if permission is granted. - * - * @uring_cmd: - * Check whether the file_operations uring_cmd is allowed to run. - * Return 0 if permission is granted. - * */ union security_list_options { #define LSM_HOOK(RET, DEFAULT, NAME, ...) RET (*NAME)(__VA_ARGS__); diff --git a/security/security.c b/security/security.c index 47506ae1b187..af1db3fa7cd0 100644 --- a/security/security.c +++ b/security/security.c @@ -4993,15 +4993,41 @@ int security_perf_event_write(struct perf_event *event) #endif /* CONFIG_PERF_EVENTS */ #ifdef CONFIG_IO_URING +/** + * security_uring_override_creds() - Check if overriding creds is allowed + * @new: new credentials + * + * Check if the current task, executing an io_uring operation, is allowed to + * override it's credentials with @new. + * + * Return: Returns 0 if permission is granted. + */ int security_uring_override_creds(const struct cred *new) { return call_int_hook(uring_override_creds, 0, new); } +/** + * security_uring_sqpoll() - Check if IORING_SETUP_SQPOLL is allowed + * + * Check whether the current task is allowed to spawn a io_uring polling thread + * (IORING_SETUP_SQPOLL). + * + * Return: Returns 0 if permission is granted. + */ int security_uring_sqpoll(void) { return call_int_hook(uring_sqpoll, 0); } + +/** + * security_uring_cmd() - Check if a io_uring passthrough command is allowed + * @ioucmd: command + * + * Check whether the file_operations uring_cmd is allowed to run. + * + * Return: Returns 0 if permission is granted. + */ int security_uring_cmd(struct io_uring_cmd *ioucmd) { return call_int_hook(uring_cmd, 0, ioucmd); From e261301c851aee401cfc63179ca4d3facd2f098b Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 16 Feb 2023 17:34:14 -0500 Subject: [PATCH 21/32] lsm: move the remaining LSM hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 168 --------------------------- security/security.c | 231 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 231 insertions(+), 168 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 8e006df1db56..ddbbe89a7a48 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -29,174 +29,6 @@ #include #include -/** - * union security_list_options - Linux Security Module hook function list - * - * @ptrace_access_check: - * Check permission before allowing the current process to trace the - * @child process. - * Security modules may also want to perform a process tracing check - * during an execve in the set_security or apply_creds hooks of - * tracing check during an execve in the bprm_set_creds hook of - * binprm_security_ops if the process is being traced and its security - * attributes would be changed by the execve. - * @child contains the task_struct structure for the target process. - * @mode contains the PTRACE_MODE flags indicating the form of access. - * Return 0 if permission is granted. - * @ptrace_traceme: - * Check that the @parent process has sufficient permission to trace the - * current process before allowing the current process to present itself - * to the @parent process for tracing. - * @parent contains the task_struct structure for debugger process. - * Return 0 if permission is granted. - * @capget: - * Get the @effective, @inheritable, and @permitted capability sets for - * the @target process. The hook may also perform permission checking to - * determine if the current process is allowed to see the capability sets - * of the @target process. - * @target contains the task_struct structure for target process. - * @effective contains the effective capability set. - * @inheritable contains the inheritable capability set. - * @permitted contains the permitted capability set. - * Return 0 if the capability sets were successfully obtained. - * @capset: - * Set the @effective, @inheritable, and @permitted capability sets for - * the current process. - * @new contains the new credentials structure for target process. - * @old contains the current credentials structure for target process. - * @effective contains the effective capability set. - * @inheritable contains the inheritable capability set. - * @permitted contains the permitted capability set. - * Return 0 and update @new if permission is granted. - * @capable: - * Check whether the @tsk process has the @cap capability in the indicated - * credentials. - * @cred contains the credentials to use. - * @ns contains the user namespace we want the capability in. - * @cap contains the capability . - * @opts contains options for the capable check . - * Return 0 if the capability is granted for @tsk. - * @quotactl: - * Check whether the quotactl syscall is allowed for this @sb. - * Return 0 if permission is granted. - * @quota_on: - * Check whether QUOTAON is allowed for this @dentry. - * Return 0 if permission is granted. - * @syslog: - * Check permission before accessing the kernel message ring or changing - * logging to the console. - * See the syslog(2) manual page for an explanation of the @type values. - * @type contains the SYSLOG_ACTION_* constant from - * . - * Return 0 if permission is granted. - * @settime: - * Check permission to change the system time. - * struct timespec64 is defined in and timezone - * is defined in - * @ts contains new time. - * @tz contains new timezone. - * Return 0 if permission is granted. - * @vm_enough_memory: - * Check permissions for allocating a new virtual mapping. - * @mm contains the mm struct it is being added to. - * @pages contains the number of pages. - * Return 0 if permission is granted by the LSM infrastructure to the - * caller. If all LSMs return a positive value, __vm_enough_memory() will - * be called with cap_sys_admin set. If at least one LSM returns 0 or - * negative, __vm_enough_memory() will be called with cap_sys_admin - * cleared. - * - * @ismaclabel: - * Check if the extended attribute specified by @name - * represents a MAC label. Returns 1 if name is a MAC - * attribute otherwise returns 0. - * @name full extended attribute name to check against - * LSM as a MAC label. - * - * @secid_to_secctx: - * Convert secid to security context. If secdata is NULL the length of - * the result will be returned in seclen, but no secdata will be returned. - * This does mean that the length could change between calls to check the - * length and the next call which actually allocates and returns the - * secdata. - * @secid contains the security ID. - * @secdata contains the pointer that stores the converted security - * context. - * @seclen pointer which contains the length of the data. - * Return 0 on success, error on failure. - * @secctx_to_secid: - * Convert security context to secid. - * @secid contains the pointer to the generated security ID. - * @secdata contains the security context. - * Return 0 on success, error on failure. - * - * @release_secctx: - * Release the security context. - * @secdata contains the security context. - * @seclen contains the length of the security context. - * - * @inode_invalidate_secctx: - * Notify the security module that it must revalidate the security context - * of an inode. - * - * @inode_notifysecctx: - * Notify the security module of what the security context of an inode - * should be. Initializes the incore security context managed by the - * security module for this inode. Example usage: NFS client invokes - * this hook to initialize the security context in its incore inode to the - * value provided by the server for the file when the server returned the - * file's attributes to the client. - * Must be called with inode->i_mutex locked. - * @inode we wish to set the security context of. - * @ctx contains the string which we wish to set in the inode. - * @ctxlen contains the length of @ctx. - * Return 0 on success, error on failure. - * - * @inode_setsecctx: - * Change the security context of an inode. Updates the - * incore security context managed by the security module and invokes the - * fs code as needed (via __vfs_setxattr_noperm) to update any backing - * xattrs that represent the context. Example usage: NFS server invokes - * this hook to change the security context in its incore inode and on the - * backing filesystem to a value provided by the client on a SETATTR - * operation. - * Must be called with inode->i_mutex locked. - * @dentry contains the inode we wish to set the security context of. - * @ctx contains the string which we wish to set in the inode. - * @ctxlen contains the length of @ctx. - * Return 0 on success, error on failure. - * - * @inode_getsecctx: - * On success, returns 0 and fills out @ctx and @ctxlen with the security - * context for the given @inode. - * @inode we wish to get the security context of. - * @ctx is a pointer in which to place the allocated security context. - * @ctxlen points to the place to put the length of @ctx. - * Return 0 on success, error on failure. - * - * Security hooks for the general notification queue: - * - * @post_notification: - * Check to see if a watch notification can be posted to a particular - * queue. - * @w_cred: The credentials of the whoever set the watch. - * @cred: The event-triggerer's credentials. - * @n: The notification being posted. - * Return 0 if permission is granted. - * - * @watch_key: - * Check to see if a process is allowed to watch for event notifications - * from a key or keyring. - * @key: The key to watch. - * Return 0 if permission is granted. - * - * @locked_down: - * Determine whether a kernel feature that potentially enables arbitrary - * code execution in kernel space should be permitted. - * @what: kernel feature being accessed. - * Return 0 if permission is granted. - * - */ union security_list_options { #define LSM_HOOK(RET, DEFAULT, NAME, ...) RET (*NAME)(__VA_ARGS__); #include "lsm_hook_defs.h" diff --git a/security/security.c b/security/security.c index af1db3fa7cd0..190a701fe444 100644 --- a/security/security.c +++ b/security/security.c @@ -838,16 +838,54 @@ int security_binder_transfer_file(const struct cred *from, return call_int_hook(binder_transfer_file, 0, from, to, file); } +/** + * security_ptrace_access_check() - Check if tracing is allowed + * @child: target process + * @mode: PTRACE_MODE flags + * + * Check permission before allowing the current process to trace the @child + * process. Security modules may also want to perform a process tracing check + * during an execve in the set_security or apply_creds hooks of tracing check + * during an execve in the bprm_set_creds hook of binprm_security_ops if the + * process is being traced and its security attributes would be changed by the + * execve. + * + * Return: Returns 0 if permission is granted. + */ int security_ptrace_access_check(struct task_struct *child, unsigned int mode) { return call_int_hook(ptrace_access_check, 0, child, mode); } +/** + * security_ptrace_traceme() - Check if tracing is allowed + * @parent: tracing process + * + * Check that the @parent process has sufficient permission to trace the + * current process before allowing the current process to present itself to the + * @parent process for tracing. + * + * Return: Returns 0 if permission is granted. + */ int security_ptrace_traceme(struct task_struct *parent) { return call_int_hook(ptrace_traceme, 0, parent); } +/** + * security_capget() - Get the capability sets for a process + * @target: target process + * @effective: effective capability set + * @inheritable: inheritable capability set + * @permitted: permitted capability set + * + * Get the @effective, @inheritable, and @permitted capability sets for the + * @target process. The hook may also perform permission checking to determine + * if the current process is allowed to see the capability sets of the @target + * process. + * + * Return: Returns 0 if the capability sets were successfully obtained. + */ int security_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, @@ -857,6 +895,19 @@ int security_capget(struct task_struct *target, effective, inheritable, permitted); } +/** + * security_capset() - Set the capability sets for a process + * @new: new credentials for the target process + * @old: current credentials of the target process + * @effective: effective capability set + * @inheritable: inheritable capability set + * @permitted: permitted capability set + * + * Set the @effective, @inheritable, and @permitted capability sets for the + * current process. + * + * Return: Returns 0 and update @new if permission is granted. + */ int security_capset(struct cred *new, const struct cred *old, const kernel_cap_t *effective, const kernel_cap_t *inheritable, @@ -866,6 +917,19 @@ int security_capset(struct cred *new, const struct cred *old, effective, inheritable, permitted); } +/** + * security_capable() - Check if a process has the necessary capability + * @cred: credentials to examine + * @ns: user namespace + * @cap: capability requested + * @opts: capability check options + * + * Check whether the @tsk process has the @cap capability in the indicated + * credentials. @cap contains the capability . + * @opts contains options for the capable check . + * + * Return: Returns 0 if the capability is granted. + */ int security_capable(const struct cred *cred, struct user_namespace *ns, int cap, @@ -874,26 +938,78 @@ int security_capable(const struct cred *cred, return call_int_hook(capable, 0, cred, ns, cap, opts); } +/** + * security_quotactl() - Check if a quotactl() syscall is allowed for this fs + * @cmds: commands + * @type: type + * @id: id + * @sb: filesystem + * + * Check whether the quotactl syscall is allowed for this @sb. + * + * Return: Returns 0 if permission is granted. + */ int security_quotactl(int cmds, int type, int id, struct super_block *sb) { return call_int_hook(quotactl, 0, cmds, type, id, sb); } +/** + * security_quota_on() - Check if QUOTAON is allowed for a dentry + * @dentry: dentry + * + * Check whether QUOTAON is allowed for @dentry. + * + * Return: Returns 0 if permission is granted. + */ int security_quota_on(struct dentry *dentry) { return call_int_hook(quota_on, 0, dentry); } +/** + * security_syslog() - Check if accessing the kernel message ring is allowed + * @type: SYSLOG_ACTION_* type + * + * Check permission before accessing the kernel message ring or changing + * logging to the console. See the syslog(2) manual page for an explanation of + * the @type values. + * + * Return: Return 0 if permission is granted. + */ int security_syslog(int type) { return call_int_hook(syslog, 0, type); } +/** + * security_settime64() - Check if changing the system time is allowed + * @ts: new time + * @tz: timezone + * + * Check permission to change the system time, struct timespec64 is defined in + * and timezone is defined in . + * + * Return: Returns 0 if permission is granted. + */ int security_settime64(const struct timespec64 *ts, const struct timezone *tz) { return call_int_hook(settime, 0, ts, tz); } +/** + * security_vm_enough_memory_mm() - Check if allocating a new mem map is allowed + * @mm: mm struct + * @pages: number of pages + * + * Check permissions for allocating a new virtual mapping. If all LSMs return + * a positive value, __vm_enough_memory() will be called with cap_sys_admin + * set. If at least one LSM returns 0 or negative, __vm_enough_memory() will be + * called with cap_sys_admin cleared. + * + * Return: Returns 0 if permission is granted by the LSM infrastructure to the + * caller. + */ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) { struct security_hook_list *hp; @@ -3703,12 +3819,33 @@ int security_netlink_send(struct sock *sk, struct sk_buff *skb) return call_int_hook(netlink_send, 0, sk, skb); } +/** + * security_ismaclabel() - Check is the named attribute is a MAC label + * @name: full extended attribute name + * + * Check if the extended attribute specified by @name represents a MAC label. + * + * Return: Returns 1 if name is a MAC attribute otherwise returns 0. + */ int security_ismaclabel(const char *name) { return call_int_hook(ismaclabel, 0, name); } EXPORT_SYMBOL(security_ismaclabel); +/** + * security_secid_to_secctx() - Convert a secid to a secctx + * @secid: secid + * @secdata: secctx + * @seclen: secctx length + * + * Convert secid to security context. If @secdata is NULL the length of the + * result will be returned in @seclen, but no @secdata will be returned. This + * does mean that the length could change between calls to check the length and + * the next call which actually allocates and returns the @secdata. + * + * Return: Return 0 on success, error on failure. + */ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) { struct security_hook_list *hp; @@ -3728,6 +3865,16 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) } EXPORT_SYMBOL(security_secid_to_secctx); +/** + * security_secctx_to_secid() - Convert a secctx to a secid + * @secdata: secctx + * @seclen: length of secctx + * @secid: secid + * + * Convert security context to secid. + * + * Return: Returns 0 on success, error on failure. + */ int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) { *secid = 0; @@ -3735,30 +3882,86 @@ int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) } EXPORT_SYMBOL(security_secctx_to_secid); +/** + * security_release_secctx() - Free a secctx buffer + * @secdata: secctx + * @seclen: length of secctx + * + * Release the security context. + */ void security_release_secctx(char *secdata, u32 seclen) { call_void_hook(release_secctx, secdata, seclen); } EXPORT_SYMBOL(security_release_secctx); +/** + * security_inode_invalidate_secctx() - Invalidate an inode's security label + * @inode: inode + * + * Notify the security module that it must revalidate the security context of + * an inode. + */ void security_inode_invalidate_secctx(struct inode *inode) { call_void_hook(inode_invalidate_secctx, inode); } EXPORT_SYMBOL(security_inode_invalidate_secctx); +/** + * security_inode_notifysecctx() - Nofify the LSM of an inode's security label + * @inode: inode + * @ctx: secctx + * @ctxlen: length of secctx + * + * Notify the security module of what the security context of an inode should + * be. Initializes the incore security context managed by the security module + * for this inode. Example usage: NFS client invokes this hook to initialize + * the security context in its incore inode to the value provided by the server + * for the file when the server returned the file's attributes to the client. + * Must be called with inode->i_mutex locked. + * + * Return: Returns 0 on success, error on failure. + */ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) { return call_int_hook(inode_notifysecctx, 0, inode, ctx, ctxlen); } EXPORT_SYMBOL(security_inode_notifysecctx); +/** + * security_inode_setsecctx() - Change the security label of an inode + * @dentry: inode + * @ctx: secctx + * @ctxlen: length of secctx + * + * Change the security context of an inode. Updates the incore security + * context managed by the security module and invokes the fs code as needed + * (via __vfs_setxattr_noperm) to update any backing xattrs that represent the + * context. Example usage: NFS server invokes this hook to change the security + * context in its incore inode and on the backing filesystem to a value + * provided by the client on a SETATTR operation. Must be called with + * inode->i_mutex locked. + * + * Return: Returns 0 on success, error on failure. + */ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) { return call_int_hook(inode_setsecctx, 0, dentry, ctx, ctxlen); } EXPORT_SYMBOL(security_inode_setsecctx); +/** + * security_inode_getsecctx() - Get the security label of an inode + * @inode: inode + * @ctx: secctx + * @ctxlen: length of secctx + * + * On success, returns 0 and fills out @ctx and @ctxlen with the security + * context for the given @inode. + * + * Return: Returns 0 on success, error on failure. + */ int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) { return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen); @@ -3766,6 +3969,16 @@ int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) EXPORT_SYMBOL(security_inode_getsecctx); #ifdef CONFIG_WATCH_QUEUE +/** + * security_post_notification() - Check if a watch notification can be posted + * @w_cred: credentials of the task that set the watch + * @cred: credentials of the task which triggered the watch + * @n: the notification + * + * Check to see if a watch notification can be posted to a particular queue. + * + * Return: Returns 0 if permission is granted. + */ int security_post_notification(const struct cred *w_cred, const struct cred *cred, struct watch_notification *n) @@ -3775,6 +3988,15 @@ int security_post_notification(const struct cred *w_cred, #endif /* CONFIG_WATCH_QUEUE */ #ifdef CONFIG_KEY_NOTIFICATIONS +/** + * security_watch_key() - Check if a task is allowed to watch for key events + * @key: the key to watch + * + * Check to see if a process is allowed to watch for event notifications from + * a key or keyring. + * + * Return: Returns 0 if permission is granted. + */ int security_watch_key(struct key *key) { return call_int_hook(watch_key, 0, key); @@ -4920,6 +5142,15 @@ void security_bpf_prog_free(struct bpf_prog_aux *aux) } #endif /* CONFIG_BPF_SYSCALL */ +/** + * security_locked_down() - Check if a kernel feature is allowed + * @what: requested kernel feature + * + * Determine whether a kernel feature that potentially enables arbitrary code + * execution in kernel space should be permitted. + * + * Return: Returns 0 if permission is granted. + */ int security_locked_down(enum lockdown_reason what) { return call_int_hook(locked_down, 0, what); From 63c1845bf1a4de21b9cb5a609c96d09e7cf6663b Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 16 Feb 2023 21:33:20 -0500 Subject: [PATCH 22/32] lsm: styling fixes to security/security.c As we were already making massive changes to security/security.c by moving all of the function header comments above the function definitions, let's take the opportunity to fix various style crimes. Acked-by: Casey Schaufler Signed-off-by: Paul Moore --- security/security.c | 182 ++++++++++++++++++++++++-------------------- 1 file changed, 98 insertions(+), 84 deletions(-) diff --git a/security/security.c b/security/security.c index 190a701fe444..f6482fd7b4b9 100644 --- a/security/security.c +++ b/security/security.c @@ -42,7 +42,7 @@ * all security modules to use the same descriptions for auditing * purposes. */ -const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = { +const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX + 1] = { [LOCKDOWN_NONE] = "none", [LOCKDOWN_MODULE_SIGNATURE] = "unsigned module loading", [LOCKDOWN_DEV_MEM] = "/dev/mem,kmem,port", @@ -88,7 +88,7 @@ static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init; static __initdata const char *chosen_lsm_order; static __initdata const char *chosen_major_lsm; -static __initconst const char * const builtin_lsm_order = CONFIG_LSM; +static __initconst const char *const builtin_lsm_order = CONFIG_LSM; /* Ordered list of LSMs to initialize. */ static __initdata struct lsm_info **ordered_lsms; @@ -332,7 +332,8 @@ static void __init report_lsm_order(void) pr_info("initializing lsm="); /* Report each enabled LSM name, comma separated. */ - for (early = __start_early_lsm_info; early < __end_early_lsm_info; early++) + for (early = __start_early_lsm_info; + early < __end_early_lsm_info; early++) if (is_enabled(early)) pr_cont("%s%s", first++ == 0 ? "" : ",", early->name); for (lsm = ordered_lsms; *lsm; lsm++) @@ -347,7 +348,7 @@ static void __init ordered_lsm_init(void) struct lsm_info **lsm; ordered_lsms = kcalloc(LSM_COUNT + 1, sizeof(*ordered_lsms), - GFP_KERNEL); + GFP_KERNEL); if (chosen_lsm_order) { if (chosen_major_lsm) { @@ -420,9 +421,9 @@ int __init security_init(void) { struct lsm_info *lsm; - init_debug("legacy security=%s\n", chosen_major_lsm ?: " *unspecified*"); + init_debug("legacy security=%s\n", chosen_major_lsm ? : " *unspecified*"); init_debug(" CONFIG_LSM=%s\n", builtin_lsm_order); - init_debug("boot arg lsm=%s\n", chosen_lsm_order ?: " *unspecified*"); + init_debug("boot arg lsm=%s\n", chosen_lsm_order ? : " *unspecified*"); /* * Append the names of the early LSM modules now that kmalloc() is @@ -510,7 +511,7 @@ static int lsm_append(const char *new, char **result) * Each LSM has to register its hooks with the infrastructure. */ void __init security_add_hooks(struct security_hook_list *hooks, int count, - const char *lsm) + const char *lsm) { int i; @@ -887,12 +888,12 @@ int security_ptrace_traceme(struct task_struct *parent) * Return: Returns 0 if the capability sets were successfully obtained. */ int security_capget(struct task_struct *target, - kernel_cap_t *effective, - kernel_cap_t *inheritable, - kernel_cap_t *permitted) + kernel_cap_t *effective, + kernel_cap_t *inheritable, + kernel_cap_t *permitted) { return call_int_hook(capget, 0, target, - effective, inheritable, permitted); + effective, inheritable, permitted); } /** @@ -914,7 +915,7 @@ int security_capset(struct cred *new, const struct cred *old, const kernel_cap_t *permitted) { return call_int_hook(capset, 0, new, old, - effective, inheritable, permitted); + effective, inheritable, permitted); } /** @@ -1348,7 +1349,7 @@ int security_sb_statfs(struct dentry *dentry) * Return: Returns 0 if permission is granted. */ int security_sb_mount(const char *dev_name, const struct path *path, - const char *type, unsigned long flags, void *data) + const char *type, unsigned long flags, void *data) { return call_int_hook(sb_mount, 0, dev_name, path, type, flags, data); } @@ -1376,7 +1377,8 @@ int security_sb_umount(struct vfsmount *mnt, int flags) * * Return: Returns 0 if permission is granted. */ -int security_sb_pivotroot(const struct path *old_path, const struct path *new_path) +int security_sb_pivotroot(const struct path *old_path, + const struct path *new_path) { return call_int_hook(sb_pivotroot, 0, old_path, new_path); } @@ -1393,13 +1395,13 @@ int security_sb_pivotroot(const struct path *old_path, const struct path *new_pa * Return: Returns 0 on success, error on failure. */ int security_sb_set_mnt_opts(struct super_block *sb, - void *mnt_opts, - unsigned long kern_flags, - unsigned long *set_kern_flags) + void *mnt_opts, + unsigned long kern_flags, + unsigned long *set_kern_flags) { return call_int_hook(sb_set_mnt_opts, - mnt_opts ? -EOPNOTSUPP : 0, sb, - mnt_opts, kern_flags, set_kern_flags); + mnt_opts ? -EOPNOTSUPP : 0, sb, + mnt_opts, kern_flags, set_kern_flags); } EXPORT_SYMBOL(security_sb_set_mnt_opts); @@ -1415,12 +1417,12 @@ EXPORT_SYMBOL(security_sb_set_mnt_opts); * Return: Returns 0 on success, error on failure. */ int security_sb_clone_mnt_opts(const struct super_block *oldsb, - struct super_block *newsb, - unsigned long kern_flags, - unsigned long *set_kern_flags) + struct super_block *newsb, + unsigned long kern_flags, + unsigned long *set_kern_flags) { return call_int_hook(sb_clone_mnt_opts, 0, oldsb, newsb, - kern_flags, set_kern_flags); + kern_flags, set_kern_flags); } EXPORT_SYMBOL(security_sb_clone_mnt_opts); @@ -1433,7 +1435,8 @@ EXPORT_SYMBOL(security_sb_clone_mnt_opts); * * Return: Returns 0 if permission is granted. */ -int security_move_mount(const struct path *from_path, const struct path *to_path) +int security_move_mount(const struct path *from_path, + const struct path *to_path) { return call_int_hook(move_mount, 0, from_path, to_path); } @@ -1450,7 +1453,7 @@ int security_move_mount(const struct path *from_path, const struct path *to_path * Return: Returns 0 if permission is granted. */ int security_path_notify(const struct path *path, u64 mask, - unsigned int obj_type) + unsigned int obj_type) { return call_int_hook(path_notify, 0, path, mask, obj_type); } @@ -1506,7 +1509,7 @@ void security_inode_free(struct inode *inode) */ if (inode->i_security) call_rcu((struct rcu_head *)inode->i_security, - inode_free_by_rcu); + inode_free_by_rcu); } /** @@ -1535,7 +1538,8 @@ int security_dentry_init_security(struct dentry *dentry, int mode, /* * Only one module will provide a security context. */ - hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security, list) { + hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security, + list) { rc = hp->hook.dentry_init_security(dentry, mode, name, xattr_name, ctx, ctxlen); if (rc != LSM_RET_DEFAULT(dentry_init_security)) @@ -1565,7 +1569,7 @@ int security_dentry_create_files_as(struct dentry *dentry, int mode, const struct cred *old, struct cred *new) { return call_int_hook(dentry_create_files_as, 0, dentry, mode, - name, old, new); + name, old, new); } EXPORT_SYMBOL(security_dentry_create_files_as); @@ -1607,9 +1611,9 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, memset(new_xattrs, 0, sizeof(new_xattrs)); lsm_xattr = new_xattrs; ret = call_int_hook(inode_init_security, -EOPNOTSUPP, inode, dir, qstr, - &lsm_xattr->name, - &lsm_xattr->value, - &lsm_xattr->value_len); + &lsm_xattr->name, + &lsm_xattr->value, + &lsm_xattr->value_len); if (ret) goto out; @@ -1669,8 +1673,8 @@ EXPORT_SYMBOL(security_old_inode_init_security); * * Return: Returns 0 if permission is granted. */ -int security_path_mknod(const struct path *dir, struct dentry *dentry, umode_t mode, - unsigned int dev) +int security_path_mknod(const struct path *dir, struct dentry *dentry, + umode_t mode, unsigned int dev) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) return 0; @@ -1688,7 +1692,8 @@ EXPORT_SYMBOL(security_path_mknod); * * Return: Returns 0 if permission is granted. */ -int security_path_mkdir(const struct path *dir, struct dentry *dentry, umode_t mode) +int security_path_mkdir(const struct path *dir, struct dentry *dentry, + umode_t mode) { if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry)))) return 0; @@ -1782,11 +1787,12 @@ int security_path_rename(const struct path *old_dir, struct dentry *old_dentry, unsigned int flags) { if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) || - (d_is_positive(new_dentry) && IS_PRIVATE(d_backing_inode(new_dentry))))) + (d_is_positive(new_dentry) && + IS_PRIVATE(d_backing_inode(new_dentry))))) return 0; return call_int_hook(path_rename, 0, old_dir, old_dentry, new_dir, - new_dentry, flags); + new_dentry, flags); } EXPORT_SYMBOL(security_path_rename); @@ -1854,7 +1860,7 @@ int security_path_chroot(const struct path *path) { return call_int_hook(path_chroot, 0, path); } -#endif +#endif /* CONFIG_SECURITY_PATH */ /** * security_inode_create() - Check if creating a file is allowed @@ -1866,7 +1872,8 @@ int security_path_chroot(const struct path *path) * * Return: Returns 0 if permission is granted. */ -int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) +int security_inode_create(struct inode *dir, struct dentry *dentry, + umode_t mode) { if (unlikely(IS_PRIVATE(dir))) return 0; @@ -1885,7 +1892,7 @@ EXPORT_SYMBOL_GPL(security_inode_create); * Return: Returns 0 if permission is granted. */ int security_inode_link(struct dentry *old_dentry, struct inode *dir, - struct dentry *new_dentry) + struct dentry *new_dentry) { if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)))) return 0; @@ -1919,7 +1926,7 @@ int security_inode_unlink(struct inode *dir, struct dentry *dentry) * Return: Returns 0 if permission is granted. */ int security_inode_symlink(struct inode *dir, struct dentry *dentry, - const char *old_name) + const char *old_name) { if (unlikely(IS_PRIVATE(dir))) return 0; @@ -1975,7 +1982,8 @@ int security_inode_rmdir(struct inode *dir, struct dentry *dentry) * * Return: Returns 0 if permission is granted. */ -int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +int security_inode_mknod(struct inode *dir, struct dentry *dentry, + umode_t mode, dev_t dev) { if (unlikely(IS_PRIVATE(dir))) return 0; @@ -1995,22 +2003,23 @@ int security_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, * Return: Returns 0 if permission is granted. */ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry, - unsigned int flags) + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) { - if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) || - (d_is_positive(new_dentry) && IS_PRIVATE(d_backing_inode(new_dentry))))) + if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) || + (d_is_positive(new_dentry) && + IS_PRIVATE(d_backing_inode(new_dentry))))) return 0; if (flags & RENAME_EXCHANGE) { int err = call_int_hook(inode_rename, 0, new_dir, new_dentry, - old_dir, old_dentry); + old_dir, old_dentry); if (err) return err; } return call_int_hook(inode_rename, 0, old_dir, old_dentry, - new_dir, new_dentry); + new_dir, new_dentry); } /** @@ -2370,7 +2379,8 @@ int security_inode_getsecurity(struct mnt_idmap *idmap, * Only one module will provide an attribute with a given name. */ hlist_for_each_entry(hp, &security_hook_heads.inode_getsecurity, list) { - rc = hp->hook.inode_getsecurity(idmap, inode, name, buffer, alloc); + rc = hp->hook.inode_getsecurity(idmap, inode, name, buffer, + alloc); if (rc != LSM_RET_DEFAULT(inode_getsecurity)) return rc; } @@ -2392,7 +2402,8 @@ int security_inode_getsecurity(struct mnt_idmap *idmap, * * Return: Returns 0 on success. */ -int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) +int security_inode_setsecurity(struct inode *inode, const char *name, + const void *value, size_t size, int flags) { struct security_hook_list *hp; int rc; @@ -2404,7 +2415,7 @@ int security_inode_setsecurity(struct inode *inode, const char *name, const void */ hlist_for_each_entry(hp, &security_hook_heads.inode_setsecurity, list) { rc = hp->hook.inode_setsecurity(inode, name, value, size, - flags); + flags); if (rc != LSM_RET_DEFAULT(inode_setsecurity)) return rc; } @@ -2424,7 +2435,8 @@ int security_inode_setsecurity(struct inode *inode, const char *name, const void * * Return: Returns number of bytes used/required on success. */ -int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) +int security_inode_listsecurity(struct inode *inode, + char *buffer, size_t buffer_size) { if (unlikely(IS_PRIVATE(inode))) return 0; @@ -2486,7 +2498,7 @@ int security_inode_copy_up_xattr(const char *name) * any other error code incase of an error. */ hlist_for_each_entry(hp, - &security_hook_heads.inode_copy_up_xattr, list) { + &security_hook_heads.inode_copy_up_xattr, list) { rc = hp->hook.inode_copy_up_xattr(name); if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr)) return rc; @@ -2646,7 +2658,7 @@ static inline unsigned long mmap_prot(struct file *file, unsigned long prot) * Return: Returns 0 if permission is granted. */ int security_mmap_file(struct file *file, unsigned long prot, - unsigned long flags) + unsigned long flags) { unsigned long prot_adj = mmap_prot(file, prot); int ret; @@ -2681,7 +2693,7 @@ int security_mmap_addr(unsigned long addr) * Return: Returns 0 if permission is granted. */ int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, - unsigned long prot) + unsigned long prot) { int ret; @@ -2754,7 +2766,7 @@ void security_file_set_fowner(struct file *file) * Return: Returns 0 if permission is granted. */ int security_file_send_sigiotask(struct task_struct *tsk, - struct fown_struct *fown, int sig) + struct fown_struct *fown, int sig) { return call_int_hook(file_send_sigiotask, 0, tsk, fown, sig); } @@ -3118,7 +3130,7 @@ int security_task_fix_setuid(struct cred *new, const struct cred *old, * Return: Returns 0 on success. */ int security_task_fix_setgid(struct cred *new, const struct cred *old, - int flags) + int flags) { return call_int_hook(task_fix_setgid, 0, new, old, flags); } @@ -3282,7 +3294,7 @@ int security_task_prlimit(const struct cred *cred, const struct cred *tcred, * Return: Returns 0 if permission is granted. */ int security_task_setrlimit(struct task_struct *p, unsigned int resource, - struct rlimit *new_rlim) + struct rlimit *new_rlim) { return call_int_hook(task_setrlimit, 0, p, resource, new_rlim); } @@ -3343,7 +3355,7 @@ int security_task_movememory(struct task_struct *p) * Return: Returns 0 if permission is granted. */ int security_task_kill(struct task_struct *p, struct kernel_siginfo *info, - int sig, const struct cred *cred) + int sig, const struct cred *cred) { return call_int_hook(task_kill, 0, p, info, sig, cred); } @@ -3363,7 +3375,7 @@ int security_task_kill(struct task_struct *p, struct kernel_siginfo *info, * to cause prctl() to return immediately with that value. */ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, - unsigned long arg4, unsigned long arg5) + unsigned long arg4, unsigned long arg5) { int thisrc; int rc = LSM_RET_DEFAULT(task_prctl); @@ -3545,7 +3557,7 @@ int security_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd) * Return: Returns 0 if permission is granted. */ int security_msg_queue_msgsnd(struct kern_ipc_perm *msq, - struct msg_msg *msg, int msqflg) + struct msg_msg *msg, int msqflg) { return call_int_hook(msg_queue_msgsnd, 0, msq, msg, msqflg); } @@ -3566,7 +3578,7 @@ int security_msg_queue_msgsnd(struct kern_ipc_perm *msq, * Return: Returns 0 if permission is granted. */ int security_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg, - struct task_struct *target, long type, int mode) + struct task_struct *target, long type, int mode) { return call_int_hook(msg_queue_msgrcv, 0, msq, msg, target, type, mode); } @@ -3649,7 +3661,8 @@ int security_shm_shmctl(struct kern_ipc_perm *shp, int cmd) * * Return: Returns 0 if permission is granted. */ -int security_shm_shmat(struct kern_ipc_perm *shp, char __user *shmaddr, int shmflg) +int security_shm_shmat(struct kern_ipc_perm *shp, + char __user *shmaddr, int shmflg) { return call_int_hook(shm_shmat, 0, shp, shmaddr, shmflg); } @@ -3732,7 +3745,7 @@ int security_sem_semctl(struct kern_ipc_perm *sma, int cmd) * Return: Returns 0 if permission is granted. */ int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops, - unsigned nsops, int alter) + unsigned nsops, int alter) { return call_int_hook(sem_semop, 0, sma, sops, nsops, alter); } @@ -4001,7 +4014,7 @@ int security_watch_key(struct key *key) { return call_int_hook(watch_key, 0, key); } -#endif +#endif /* CONFIG_KEY_NOTIFICATIONS */ #ifdef CONFIG_SECURITY_NETWORK /** @@ -4025,7 +4038,8 @@ int security_watch_key(struct key *key) * * Return: Returns 0 if permission is granted. */ -int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk) +int security_unix_stream_connect(struct sock *sock, struct sock *other, + struct sock *newsk) { return call_int_hook(unix_stream_connect, 0, sock, other, newsk); } @@ -4095,7 +4109,7 @@ int security_socket_post_create(struct socket *sock, int family, int type, int protocol, int kern) { return call_int_hook(socket_post_create, 0, sock, family, type, - protocol, kern); + protocol, kern); } /** @@ -4126,7 +4140,8 @@ EXPORT_SYMBOL(security_socket_socketpair); * * Return: Returns 0 if permission is granted. */ -int security_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) +int security_socket_bind(struct socket *sock, + struct sockaddr *address, int addrlen) { return call_int_hook(socket_bind, 0, sock, address, addrlen); } @@ -4142,7 +4157,8 @@ int security_socket_bind(struct socket *sock, struct sockaddr *address, int addr * * Return: Returns 0 if permission is granted. */ -int security_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) +int security_socket_connect(struct socket *sock, + struct sockaddr *address, int addrlen) { return call_int_hook(socket_connect, 0, sock, address, addrlen); } @@ -4336,7 +4352,8 @@ int security_socket_getpeersec_stream(struct socket *sock, sockptr_t optval, * * Return: Returns 0 on success, error on failure. */ -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) +int security_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, u32 *secid) { return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock, skb, secid); @@ -4428,7 +4445,7 @@ EXPORT_SYMBOL(security_sock_graft); * Return: Returns 0 if permission is granted. */ int security_inet_conn_request(const struct sock *sk, - struct sk_buff *skb, struct request_sock *req) + struct sk_buff *skb, struct request_sock *req) { return call_int_hook(inet_conn_request, 0, sk, skb, req); } @@ -4442,7 +4459,7 @@ EXPORT_SYMBOL(security_inet_conn_request); * Set that LSM state of @sock using the LSM state from @req. */ void security_inet_csk_clone(struct sock *newsk, - const struct request_sock *req) + const struct request_sock *req) { call_void_hook(inet_csk_clone, newsk, req); } @@ -4455,7 +4472,7 @@ void security_inet_csk_clone(struct sock *newsk, * Update @sock's LSM state to represent a new connection from @skb. */ void security_inet_conn_established(struct sock *sk, - struct sk_buff *skb) + struct sk_buff *skb) { call_void_hook(inet_conn_established, sk, skb); } @@ -4591,7 +4608,8 @@ EXPORT_SYMBOL(security_tun_dev_open); * * Return: Returns 0 on success, error on failure. */ -int security_sctp_assoc_request(struct sctp_association *asoc, struct sk_buff *skb) +int security_sctp_assoc_request(struct sctp_association *asoc, + struct sk_buff *skb) { return call_int_hook(sctp_assoc_request, 0, asoc, skb); } @@ -4656,7 +4674,6 @@ EXPORT_SYMBOL(security_sctp_assoc_established); #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_INFINIBAND - /** * security_ib_pkey_access() - Check if access to an IB pkey is allowed * @sec: LSM blob @@ -4683,9 +4700,11 @@ EXPORT_SYMBOL(security_ib_pkey_access); * * Return: Returns 0 if permission is granted. */ -int security_ib_endport_manage_subnet(void *sec, const char *dev_name, u8 port_num) +int security_ib_endport_manage_subnet(void *sec, + const char *dev_name, u8 port_num) { - return call_int_hook(ib_endport_manage_subnet, 0, sec, dev_name, port_num); + return call_int_hook(ib_endport_manage_subnet, 0, sec, + dev_name, port_num); } EXPORT_SYMBOL(security_ib_endport_manage_subnet); @@ -4717,7 +4736,6 @@ EXPORT_SYMBOL(security_ib_free_security); #endif /* CONFIG_SECURITY_INFINIBAND */ #ifdef CONFIG_SECURITY_NETWORK_XFRM - /** * security_xfrm_policy_alloc() - Allocate a xfrm policy LSM blob * @ctxp: xfrm security context being added to the SPD @@ -4748,7 +4766,7 @@ EXPORT_SYMBOL(security_xfrm_policy_alloc); * Return: Return 0 if operation was successful. */ int security_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx, - struct xfrm_sec_ctx **new_ctxp) + struct xfrm_sec_ctx **new_ctxp) { return call_int_hook(xfrm_policy_clone_security, 0, old_ctx, new_ctxp); } @@ -4883,7 +4901,7 @@ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, * using the macro */ hlist_for_each_entry(hp, &security_hook_heads.xfrm_state_pol_flow_match, - list) { + list) { rc = hp->hook.xfrm_state_pol_flow_match(x, xp, flic); break; } @@ -4907,16 +4925,14 @@ int security_xfrm_decode_session(struct sk_buff *skb, u32 *secid) void security_skb_classify_flow(struct sk_buff *skb, struct flowi_common *flic) { int rc = call_int_hook(xfrm_decode_session, 0, skb, &flic->flowic_secid, - 0); + 0); BUG_ON(rc); } EXPORT_SYMBOL(security_skb_classify_flow); - #endif /* CONFIG_SECURITY_NETWORK_XFRM */ #ifdef CONFIG_KEYS - /** * security_key_alloc() - Allocate and initialize a kernel key LSM blob * @key: key @@ -4979,11 +4995,9 @@ int security_key_getsecurity(struct key *key, char **_buffer) *_buffer = NULL; return call_int_hook(key_getsecurity, 0, key, _buffer); } - #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT - /** * security_audit_rule_init() - Allocate and init an LSM audit rule struct * @field: audit action From 1e2523d745cff3c5c066e66299d3cf179baa3cbc Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 8 Mar 2023 12:31:03 -0500 Subject: [PATCH 23/32] lsm: fix doc warnings in the LSM hook comments Signed-off-by: Paul Moore --- security/security.c | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/security/security.c b/security/security.c index f6482fd7b4b9..4c39cfe313bf 100644 --- a/security/security.c +++ b/security/security.c @@ -1228,7 +1228,7 @@ void security_sb_free(struct super_block *sb) /** * security_free_mnt_opts() - Free memory associated with mount options - * @mnt_ops: LSM processed mount options + * @mnt_opts: LSM processed mount options * * Free memory associated with @mnt_ops. */ @@ -1244,7 +1244,7 @@ EXPORT_SYMBOL(security_free_mnt_opts); /** * security_sb_eat_lsm_opts() - Consume LSM mount options * @options: mount options - * @mnt_ops: LSM processed mount options + * @mnt_opts: LSM processed mount options * * Eat (scan @options) and save them in @mnt_opts. * @@ -1407,8 +1407,8 @@ EXPORT_SYMBOL(security_sb_set_mnt_opts); /** * security_sb_clone_mnt_opts() - Duplicate superblock mount options - * @olddb: source superblock - * @newdb: destination superblock + * @oldsb: source superblock + * @newsb: destination superblock * @kern_flags: kernel flags (in) * @set_kern_flags: kernel flags (out) * @@ -1916,7 +1916,7 @@ int security_inode_unlink(struct inode *dir, struct dentry *dentry) } /** - * security_inode_symlink() Check if creating a symbolic link is allowed + * security_inode_symlink() - Check if creating a symbolic link is allowed * @dir: parent directory * @dentry: symbolic link * @old_name: existing filename @@ -2125,6 +2125,7 @@ int security_inode_getattr(const struct path *path) * @dentry: file * @name: xattr name * @value: xattr value + * @size: size of xattr value * @flags: flags * * Check permission before setting the extended attributes. @@ -2686,7 +2687,7 @@ int security_mmap_addr(unsigned long addr) * security_file_mprotect() - Check if changing memory protections is allowed * @vma: memory region * @reqprot: application requested protection - * @prog: protection applied by the kernel + * @prot: protection applied by the kernel * * Check permissions before changing memory access permissions. * @@ -3421,7 +3422,7 @@ int security_create_user_ns(const struct cred *cred) /** * security_ipc_permission() - Check if sysv ipc access is allowed * @ipcp: ipc permission structure - * @flags: requested permissions + * @flag: requested permissions * * Check permissions for access to IPC. * @@ -3718,7 +3719,7 @@ int security_sem_associate(struct kern_ipc_perm *sma, int semflg) } /** - * security_sem_ctl() - Check if a sysv semaphore operation is allowed + * security_sem_semctl() - Check if a sysv semaphore operation is allowed * @sma: sysv ipc permission structure * @cmd: operation * @@ -4088,7 +4089,7 @@ int security_socket_create(int family, int type, int protocol, int kern) } /** - * security_socket_create() - Initialize a newly created socket + * security_socket_post_create() - Initialize a newly created socket * @sock: socket * @family: protocol family * @type: communications type @@ -4364,7 +4365,7 @@ EXPORT_SYMBOL(security_socket_getpeersec_dgram); * security_sk_alloc() - Allocate and initialize a sock's LSM blob * @sk: sock * @family: protocol family - * @priotity: gfp flags + * @priority: gfp flags * * Allocate and attach a security structure to the sk->sk_security field, which * is used to copy security attributes between local stream sockets. @@ -4423,10 +4424,10 @@ EXPORT_SYMBOL(security_req_classify_flow); /** * security_sock_graft() - Reconcile LSM state when grafting a sock on a socket * @sk: sock being grafted - * @sock: target socket + * @parent: target parent socket * - * Sets @sock's inode secid to @sk's secid and update @sk with any necessary - * LSM state from @sock. + * Sets @parent's inode secid to @sk's secid and update @sk with any necessary + * LSM state from @parent. */ void security_sock_graft(struct sock *sk, struct socket *parent) { @@ -4877,7 +4878,7 @@ int security_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid) /** * security_xfrm_state_pol_flow_match() - Check for a xfrm match * @x: xfrm state to match - * @xp xfrm policy to check for a match + * @xp: xfrm policy to check for a match * @flic: flow to check for a match. * * Check @xp and @flic for a match with @x. @@ -4980,13 +4981,13 @@ int security_key_permission(key_ref_t key_ref, const struct cred *cred, /** * security_key_getsecurity() - Get the key's security label * @key: key - * @buffer: security label buffer + * @_buffer: security label buffer * * Get a textual representation of the security context attached to a key for * the purposes of honouring KEYCTL_GETSECURITY. This function allocates the * storage for the NUL-terminated string and the caller should free it. * - * Return: Returns the length of @buffer (including terminating NUL) or -ve if + * Return: Returns the length of @_buffer (including terminating NUL) or -ve if * an error occurs. May also return 0 (and a NULL buffer pointer) if * there is no security label assigned to the key. */ From b3816cf8138b6814375ec65673bcba91d368ee9f Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 8 Mar 2023 13:28:18 -0500 Subject: [PATCH 24/32] lsm: fix a badly named parameter in security_get_getsecurity() There is no good reason for why the "_buffer" parameter needs an underscore, get rid of it. Signed-off-by: Paul Moore --- include/linux/lsm_hook_defs.h | 2 +- security/security.c | 10 +++++----- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 094b76dc7164..6bb55e61e8e8 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -381,7 +381,7 @@ LSM_HOOK(int, 0, key_alloc, struct key *key, const struct cred *cred, LSM_HOOK(void, LSM_RET_VOID, key_free, struct key *key) LSM_HOOK(int, 0, key_permission, key_ref_t key_ref, const struct cred *cred, enum key_need_perm need_perm) -LSM_HOOK(int, 0, key_getsecurity, struct key *key, char **_buffer) +LSM_HOOK(int, 0, key_getsecurity, struct key *key, char **buffer) #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT diff --git a/security/security.c b/security/security.c index 4c39cfe313bf..e6c275fff001 100644 --- a/security/security.c +++ b/security/security.c @@ -4981,20 +4981,20 @@ int security_key_permission(key_ref_t key_ref, const struct cred *cred, /** * security_key_getsecurity() - Get the key's security label * @key: key - * @_buffer: security label buffer + * @buffer: security label buffer * * Get a textual representation of the security context attached to a key for * the purposes of honouring KEYCTL_GETSECURITY. This function allocates the * storage for the NUL-terminated string and the caller should free it. * - * Return: Returns the length of @_buffer (including terminating NUL) or -ve if + * Return: Returns the length of @buffer (including terminating NUL) or -ve if * an error occurs. May also return 0 (and a NULL buffer pointer) if * there is no security label assigned to the key. */ -int security_key_getsecurity(struct key *key, char **_buffer) +int security_key_getsecurity(struct key *key, char **buffer) { - *_buffer = NULL; - return call_int_hook(key_getsecurity, 0, key, _buffer); + *buffer = NULL; + return call_int_hook(key_getsecurity, 0, key, buffer); } #endif /* CONFIG_KEYS */ From f89f8e1661e6bef87073ad4934e1eede5f69f4b7 Mon Sep 17 00:00:00 2001 From: Kamalesh Babulal Date: Sat, 4 Mar 2023 12:59:23 +0530 Subject: [PATCH 25/32] device_cgroup: Fix typo in devcgroup_css_alloc description Fix the stale cgroup.c path in the devcgroup_css_alloc() description. Signed-off-by: Kamalesh Babulal Signed-off-by: Paul Moore --- security/device_cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/device_cgroup.c b/security/device_cgroup.c index bef2b9285fb3..7507d14eacc7 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -216,7 +216,7 @@ static void devcgroup_offline(struct cgroup_subsys_state *css) } /* - * called from kernel/cgroup.c with cgroup_lock() held. + * called from kernel/cgroup/cgroup.c with cgroup_lock() held. */ static struct cgroup_subsys_state * devcgroup_css_alloc(struct cgroup_subsys_state *parent_css) From 42994ee3cd7298b27698daa6848ed7168e72d056 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Fri, 10 Mar 2023 09:53:59 +0100 Subject: [PATCH 26/32] security: Introduce LSM_ORDER_LAST and set it for the integrity LSM Introduce LSM_ORDER_LAST, to satisfy the requirement of LSMs needing to be last, e.g. the 'integrity' LSM, without changing the kernel command line or configuration. Also, set this order for the 'integrity' LSM. While not enforced, this is the only LSM expected to use it. Similarly to LSM_ORDER_FIRST, LSMs with LSM_ORDER_LAST are always enabled and put at the end of the LSM list, if selected in the kernel configuration. Setting one of these orders alone, does not cause the LSMs to be selected and compiled built-in in the kernel. Finally, for LSM_ORDER_MUTABLE LSMs, set the found variable to true if an LSM is found, regardless of its order. In this way, the kernel would not wrongly report that the LSM is not built-in in the kernel if its order is LSM_ORDER_LAST. Fixes: 79f7865d844c ("LSM: Introduce "lsm=" for boottime LSM selection") Signed-off-by: Roberto Sassu Acked-by: Mimi Zohar Signed-off-by: Paul Moore --- include/linux/lsm_hooks.h | 1 + security/integrity/iint.c | 1 + security/security.c | 12 +++++++++--- 3 files changed, 11 insertions(+), 3 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index ddbbe89a7a48..c2be66c669ae 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -92,6 +92,7 @@ extern void security_add_hooks(struct security_hook_list *hooks, int count, enum lsm_order { LSM_ORDER_FIRST = -1, /* This is only for capabilities. */ LSM_ORDER_MUTABLE = 0, + LSM_ORDER_LAST = 1, /* This is only for integrity. */ }; struct lsm_info { diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 8638976f7990..b97eb59e0e32 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -182,6 +182,7 @@ static int __init integrity_iintcache_init(void) DEFINE_LSM(integrity) = { .name = "integrity", .init = integrity_iintcache_init, + .order = LSM_ORDER_LAST, }; diff --git a/security/security.c b/security/security.c index e6c275fff001..b808e1b86551 100644 --- a/security/security.c +++ b/security/security.c @@ -285,9 +285,9 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) bool found = false; for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { - if (lsm->order == LSM_ORDER_MUTABLE && - strcmp(lsm->name, name) == 0) { - append_ordered_lsm(lsm, origin); + if (strcmp(lsm->name, name) == 0) { + if (lsm->order == LSM_ORDER_MUTABLE) + append_ordered_lsm(lsm, origin); found = true; } } @@ -307,6 +307,12 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) } } + /* LSM_ORDER_LAST is always last. */ + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if (lsm->order == LSM_ORDER_LAST) + append_ordered_lsm(lsm, " last"); + } + /* Disable all LSMs not in the ordered list. */ for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { if (exists_ordered_lsm(lsm)) From b7c1ae4bcc5b7e737b46d469959446afc76d3165 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Fri, 10 Mar 2023 09:54:00 +0100 Subject: [PATCH 27/32] Revert "integrity: double check iint_cache was initialized" With the recent introduction of LSM_ORDER_LAST, the 'integrity' LSM is always initialized (if selected in the kernel configuration) and the iint_cache is always created (the kernel panics on error). Thus, the additional check of iint_cache in integrity_inode_get() is no longer necessary. If the 'integrity' LSM is not selected in the kernel configuration, integrity_inode_get() just returns NULL. This reverts commit 92063f3ca73aab794bd5408d3361fd5b5ea33079. Signed-off-by: Roberto Sassu Acked-by: Mimi Zohar Signed-off-by: Paul Moore --- security/integrity/iint.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/security/integrity/iint.c b/security/integrity/iint.c index b97eb59e0e32..c73858e8c6d5 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -98,14 +98,6 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode) struct rb_node *node, *parent = NULL; struct integrity_iint_cache *iint, *test_iint; - /* - * The integrity's "iint_cache" is initialized at security_init(), - * unless it is not included in the ordered list of LSMs enabled - * on the boot command line. - */ - if (!iint_cache) - panic("%s: lsm=integrity required.\n", __func__); - iint = integrity_iint_find(inode); if (iint) return iint; From b9b8701b43146f5ebd7fe13d89103cfc545cda34 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Fri, 10 Mar 2023 09:54:01 +0100 Subject: [PATCH 28/32] security: Remove integrity from the LSM list in Kconfig Remove 'integrity' from the list of LSMs in Kconfig, as it is no longer necessary. Since the recent change (set order to LSM_ORDER_LAST), the 'integrity' LSM is always enabled (if selected in the kernel configuration). Signed-off-by: Roberto Sassu Acked-by: Mimi Zohar Signed-off-by: Paul Moore --- security/Kconfig | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/security/Kconfig b/security/Kconfig index e6db09a779b7..1699dda68216 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -246,15 +246,17 @@ endchoice config LSM string "Ordered list of enabled LSMs" - default "landlock,lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK - default "landlock,lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR - default "landlock,lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO - default "landlock,lockdown,yama,loadpin,safesetid,integrity,bpf" if DEFAULT_SECURITY_DAC - default "landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf" + default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK + default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR + default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO + default "landlock,lockdown,yama,loadpin,safesetid,bpf" if DEFAULT_SECURITY_DAC + default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf" help A comma-separated list of LSMs, in initialization order. - Any LSMs left off this list will be ignored. This can be - controlled at boot with the "lsm=" parameter. + Any LSMs left off this list, except for those with order + LSM_ORDER_FIRST and LSM_ORDER_LAST, which are always enabled + if selected in the kernel configuration, will be ignored. + This can be controlled at boot with the "lsm=" parameter. If unsure, leave this as the default. From 52ca4b6435a493e47aaa98e7345e19e1e8710b13 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Tue, 14 Mar 2023 09:17:15 +0100 Subject: [PATCH 29/32] reiserfs: Switch to security_inode_init_security() In preparation for removing security_old_inode_init_security(), switch to security_inode_init_security(). Commit 572302af1258 ("reiserfs: Add missing calls to reiserfs_security_free()") fixed possible memory leaks and another issue related to adding an xattr at inode creation time. Define the initxattrs callback reiserfs_initxattrs(), to populate the name/value/len triple in the reiserfs_security_handle() with the first xattr provided by LSMs. Make a copy of the xattr value, as security_inode_init_security() frees it. After the call to security_inode_init_security(), remove the check for returning -EOPNOTSUPP, as security_inode_init_security() changes it to zero. Multiple xattrs are currently not supported, as the reiserfs_security_handle structure is exported to user space. As a consequence, even if EVM is invoked, it will not provide an xattr (if it is not the first to set it, its xattr will be discarded; if it is the first, it does not have xattrs to calculate the HMAC on). Signed-off-by: Roberto Sassu Reviewed-by: Casey Schaufler Reviewed-by: Mimi Zohar Signed-off-by: Paul Moore --- fs/reiserfs/xattr_security.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c index 41c0ea84fbff..6bffdf9a4fd2 100644 --- a/fs/reiserfs/xattr_security.c +++ b/fs/reiserfs/xattr_security.c @@ -39,6 +39,22 @@ static bool security_list(struct dentry *dentry) return !IS_PRIVATE(d_inode(dentry)); } +static int +reiserfs_initxattrs(struct inode *inode, const struct xattr *xattr_array, + void *fs_info) +{ + struct reiserfs_security_handle *sec = fs_info; + + sec->value = kmemdup(xattr_array->value, xattr_array->value_len, + GFP_KERNEL); + if (!sec->value) + return -ENOMEM; + + sec->name = xattr_array->name; + sec->length = xattr_array->value_len; + return 0; +} + /* Initializes the security context for a new inode and returns the number * of blocks needed for the transaction. If successful, reiserfs_security * must be released using reiserfs_security_free when the caller is done. */ @@ -56,12 +72,9 @@ int reiserfs_security_init(struct inode *dir, struct inode *inode, if (IS_PRIVATE(dir)) return 0; - error = security_old_inode_init_security(inode, dir, qstr, &sec->name, - &sec->value, &sec->length); + error = security_inode_init_security(inode, dir, qstr, + &reiserfs_initxattrs, sec); if (error) { - if (error == -EOPNOTSUPP) - error = 0; - sec->name = NULL; sec->value = NULL; sec->length = 0; From de3004c874e740304cc4f4a83d6200acb511bbda Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Tue, 14 Mar 2023 09:17:16 +0100 Subject: [PATCH 30/32] ocfs2: Switch to security_inode_init_security() In preparation for removing security_old_inode_init_security(), switch to security_inode_init_security(). Extend the existing ocfs2_initxattrs() to take the ocfs2_security_xattr_info structure from fs_info, and populate the name/value/len triple with the first xattr provided by LSMs. As fs_info was not used before, ocfs2_initxattrs() can now handle the case of replicating the behavior of security_old_inode_init_security(), i.e. just obtaining the xattr, in addition to setting all xattrs provided by LSMs. Supporting multiple xattrs is not currently supported where security_old_inode_init_security() was called (mknod, symlink), as it requires non-trivial changes that can be done at a later time. Like for reiserfs, even if EVM is invoked, it will not provide an xattr (if it is not the first to set it, its xattr will be discarded; if it is the first, it does not have xattrs to calculate the HMAC on). Finally, since security_inode_init_security(), unlike security_old_inode_init_security(), returns zero instead of -EOPNOTSUPP if no xattrs were provided by LSMs or if inodes are private, additionally check in ocfs2_init_security_get() if the xattr name is set. If not, act as if security_old_inode_init_security() returned -EOPNOTSUPP, and set si->enable to zero to notify to the functions following ocfs2_init_security_get() that no xattrs are available. Signed-off-by: Roberto Sassu Reviewed-by: Casey Schaufler Acked-by: Joseph Qi Reviewed-by: Mimi Zohar Signed-off-by: Paul Moore --- fs/ocfs2/namei.c | 2 ++ fs/ocfs2/xattr.c | 30 ++++++++++++++++++++++++++---- 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c index 9175dbc47201..17c52225b87d 100644 --- a/fs/ocfs2/namei.c +++ b/fs/ocfs2/namei.c @@ -242,6 +242,7 @@ static int ocfs2_mknod(struct mnt_idmap *idmap, int want_meta = 0; int xattr_credits = 0; struct ocfs2_security_xattr_info si = { + .name = NULL, .enable = 1, }; int did_quota_inode = 0; @@ -1805,6 +1806,7 @@ static int ocfs2_symlink(struct mnt_idmap *idmap, int want_clusters = 0; int xattr_credits = 0; struct ocfs2_security_xattr_info si = { + .name = NULL, .enable = 1, }; int did_quota = 0, did_quota_inode = 0; diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index 389308efe854..469ec45baee2 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -7259,9 +7259,21 @@ static int ocfs2_xattr_security_set(const struct xattr_handler *handler, static int ocfs2_initxattrs(struct inode *inode, const struct xattr *xattr_array, void *fs_info) { + struct ocfs2_security_xattr_info *si = fs_info; const struct xattr *xattr; int err = 0; + if (si) { + si->value = kmemdup(xattr_array->value, xattr_array->value_len, + GFP_KERNEL); + if (!si->value) + return -ENOMEM; + + si->name = xattr_array->name; + si->value_len = xattr_array->value_len; + return 0; + } + for (xattr = xattr_array; xattr->name != NULL; xattr++) { err = ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_SECURITY, xattr->name, xattr->value, @@ -7277,13 +7289,23 @@ int ocfs2_init_security_get(struct inode *inode, const struct qstr *qstr, struct ocfs2_security_xattr_info *si) { + int ret; + /* check whether ocfs2 support feature xattr */ if (!ocfs2_supports_xattr(OCFS2_SB(dir->i_sb))) return -EOPNOTSUPP; - if (si) - return security_old_inode_init_security(inode, dir, qstr, - &si->name, &si->value, - &si->value_len); + if (si) { + ret = security_inode_init_security(inode, dir, qstr, + &ocfs2_initxattrs, si); + /* + * security_inode_init_security() does not return -EOPNOTSUPP, + * we have to check the xattr ourselves. + */ + if (!ret && !si->name) + si->enable = 0; + + return ret; + } return security_inode_init_security(inode, dir, qstr, &ocfs2_initxattrs, NULL); From 0d57b970df352517a75f4533820c49de360c4123 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Tue, 14 Mar 2023 09:17:17 +0100 Subject: [PATCH 31/32] security: Remove security_old_inode_init_security() As the remaining two users reiserfs and ocfs2 switched to security_inode_init_security(), security_old_inode_init_security() can be now removed. Out-of-tree kernel modules should switch to security_inode_init_security() too. Signed-off-by: Roberto Sassu Reviewed-by: Casey Schaufler Reviewed-by: Mimi Zohar Signed-off-by: Paul Moore --- include/linux/security.h | 12 ------------ security/security.c | 11 ----------- 2 files changed, 23 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 5984d0d550b4..cd23221ce9e6 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -336,9 +336,6 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, int security_inode_init_security_anon(struct inode *inode, const struct qstr *name, const struct inode *context_inode); -int security_old_inode_init_security(struct inode *inode, struct inode *dir, - const struct qstr *qstr, const char **name, - void **value, size_t *len); int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode); int security_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry); @@ -778,15 +775,6 @@ static inline int security_inode_init_security_anon(struct inode *inode, return 0; } -static inline int security_old_inode_init_security(struct inode *inode, - struct inode *dir, - const struct qstr *qstr, - const char **name, - void **value, size_t *len) -{ - return -EOPNOTSUPP; -} - static inline int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) diff --git a/security/security.c b/security/security.c index b808e1b86551..f4170efcddda 100644 --- a/security/security.c +++ b/security/security.c @@ -1655,17 +1655,6 @@ int security_inode_init_security_anon(struct inode *inode, context_inode); } -int security_old_inode_init_security(struct inode *inode, struct inode *dir, - const struct qstr *qstr, const char **name, - void **value, size_t *len) -{ - if (unlikely(IS_PRIVATE(inode))) - return -EOPNOTSUPP; - return call_int_hook(inode_init_security, -EOPNOTSUPP, inode, dir, - qstr, name, value, len); -} -EXPORT_SYMBOL(security_old_inode_init_security); - #ifdef CONFIG_SECURITY_PATH /** * security_path_mknod() - Check if creating a special file is allowed From d82dcd9e21b77d338dc4875f3d4111f0db314a7c Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Fri, 31 Mar 2023 14:32:18 +0200 Subject: [PATCH 32/32] reiserfs: Add security prefix to xattr name in reiserfs_security_write() Reiserfs sets a security xattr at inode creation time in two stages: first, it calls reiserfs_security_init() to obtain the xattr from active LSMs; then, it calls reiserfs_security_write() to actually write that xattr. Unfortunately, it seems there is a wrong expectation that LSMs provide the full xattr name in the form 'security.'. However, LSMs always provided just the suffix, causing reiserfs to not write the xattr at all (if the suffix is shorter than the prefix), or to write an xattr with the wrong name. Add a temporary buffer in reiserfs_security_write(), and write to it the full xattr name, before passing it to reiserfs_xattr_set_handle(). Also replace the name length check with a check that the full xattr name is not larger than XATTR_NAME_MAX. Cc: stable@vger.kernel.org # v2.6.x Fixes: 57fe60df6241 ("reiserfs: add atomic addition of selinux attributes during inode creation") Signed-off-by: Roberto Sassu Signed-off-by: Paul Moore --- fs/reiserfs/xattr_security.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c index 6bffdf9a4fd2..6e0a099dd788 100644 --- a/fs/reiserfs/xattr_security.c +++ b/fs/reiserfs/xattr_security.c @@ -95,11 +95,15 @@ int reiserfs_security_write(struct reiserfs_transaction_handle *th, struct inode *inode, struct reiserfs_security_handle *sec) { + char xattr_name[XATTR_NAME_MAX + 1] = XATTR_SECURITY_PREFIX; int error; - if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX)) + + if (XATTR_SECURITY_PREFIX_LEN + strlen(sec->name) > XATTR_NAME_MAX) return -EINVAL; - error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value, + strlcat(xattr_name, sec->name, sizeof(xattr_name)); + + error = reiserfs_xattr_set_handle(th, inode, xattr_name, sec->value, sec->length, XATTR_CREATE); if (error == -ENODATA || error == -EOPNOTSUPP) error = 0;