linux/security
Christian Brauner e65ce2a50c
acl: handle idmapped mounts
The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.

The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.

In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.

Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:17 +01:00
..
apparmor apparmor: remove duplicate macro list_entry_is_head() 2020-12-15 22:46:19 -08:00
bpf bpf: Implement task local storage 2020-11-06 08:08:37 -08:00
integrity EFI updates collected by Ard Biesheuvel: 2020-12-24 12:40:07 -08:00
keys Networking updates for 5.11 2020-12-15 13:22:29 -08:00
loadpin LSM: Add "contents" flag to kernel_read_file hook 2020-10-05 13:37:03 +02:00
lockdown Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2020-06-02 17:36:24 -07:00
safesetid LSM: SafeSetID: Fix warnings reported by test bot 2020-10-13 09:17:36 -07:00
selinux inode: make init and permission helpers idmapped mount aware 2021-01-24 14:27:16 +01:00
smack Provide a fix for the incorrect handling of privilege 2020-12-24 14:08:43 -08:00
tomoyo tomoyo: Fix typo in comments. 2020-12-06 13:44:57 +09:00
yama task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00
commoncap.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
device_cgroup.c device_cgroup: Fix RCU list debugging warning 2020-08-20 11:25:03 -07:00
inode.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
Kconfig Replace HTTP links with HTTPS ones: security 2020-08-06 12:00:05 -07:00
Kconfig.hardening security: allow using Clang's zero initialization for stack variables 2020-06-16 02:06:23 -07:00
lsm_audit.c dump_common_audit_data(): fix racy accesses to ->d_name 2021-01-16 15:11:35 -05:00
Makefile device_cgroup: Cleanup cgroup eBPF device filter code 2020-04-13 14:41:54 -04:00
min_addr.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
security.c selinux/stable-5.11 PR 20201214 2020-12-16 11:01:04 -08:00