linux/fs/btrfs/acl.c
Chengguang Xu ab3629ed86 btrfs: return error instead of crash when detecting unexpected type in btrfs_get_acl
The caller of btrfs_get_acl() checks error condition so there is no
impact from this change. In practice there is no chance to get into
default case of switch statement because VFS has already checked the
type.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:40 +02:00

145 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Red Hat. All rights reserved.
*/
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/posix_acl.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include "ctree.h"
#include "btrfs_inode.h"
#include "xattr.h"
struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
{
int size;
const char *name;
char *value = NULL;
struct posix_acl *acl;
switch (type) {
case ACL_TYPE_ACCESS:
name = XATTR_NAME_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
name = XATTR_NAME_POSIX_ACL_DEFAULT;
break;
default:
return ERR_PTR(-EINVAL);
}
size = btrfs_getxattr(inode, name, "", 0);
if (size > 0) {
value = kzalloc(size, GFP_KERNEL);
if (!value)
return ERR_PTR(-ENOMEM);
size = btrfs_getxattr(inode, name, value, size);
}
if (size > 0) {
acl = posix_acl_from_xattr(&init_user_ns, value, size);
} else if (size == -ERANGE || size == -ENODATA || size == 0) {
acl = NULL;
} else {
acl = ERR_PTR(-EIO);
}
kfree(value);
return acl;
}
static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
struct inode *inode, struct posix_acl *acl, int type)
{
int ret, size = 0;
const char *name;
char *value = NULL;
switch (type) {
case ACL_TYPE_ACCESS:
name = XATTR_NAME_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode))
return acl ? -EINVAL : 0;
name = XATTR_NAME_POSIX_ACL_DEFAULT;
break;
default:
return -EINVAL;
}
if (acl) {
size = posix_acl_xattr_size(acl->a_count);
value = kmalloc(size, GFP_KERNEL);
if (!value) {
ret = -ENOMEM;
goto out;
}
ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
if (ret < 0)
goto out;
}
ret = btrfs_setxattr(trans, inode, name, value, size, 0);
out:
kfree(value);
if (!ret)
set_cached_acl(inode, type, acl);
return ret;
}
int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
int ret;
umode_t old_mode = inode->i_mode;
if (type == ACL_TYPE_ACCESS && acl) {
ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
if (ret)
return ret;
}
ret = __btrfs_set_acl(NULL, inode, acl, type);
if (ret)
inode->i_mode = old_mode;
return ret;
}
int btrfs_init_acl(struct btrfs_trans_handle *trans,
struct inode *inode, struct inode *dir)
{
struct posix_acl *default_acl, *acl;
int ret = 0;
/* this happens with subvols */
if (!dir)
return 0;
ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
if (ret)
return ret;
if (default_acl) {
ret = __btrfs_set_acl(trans, inode, default_acl,
ACL_TYPE_DEFAULT);
posix_acl_release(default_acl);
}
if (acl) {
if (!ret)
ret = __btrfs_set_acl(trans, inode, acl,
ACL_TYPE_ACCESS);
posix_acl_release(acl);
}
if (!default_acl && !acl)
cache_no_acl(inode);
return ret;
}