[patch 126/149] Btrfs: should add a permission check for setfacl

Greg KH
2010-07-01T18:31:01Z

2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Shi Weihua <shiwh@cn.fujitsu.com>

commit 2f26afba46f0ebf155cf9be746496a0304a5b7cf upstream.

On btrfs, do the following
------------------
# su user1
# cd btrfs-part/
# touch aaa
# getfacl aaa
# file: aaa
# owner: user1
# group: user1
user::rw-
group::rw-
other::r--
# su user2
# cd btrfs-part/
# setfacl -m u::rwx aaa
# getfacl aaa
# file: aaa
# owner: user1
# group: user1
user::rwx <- successed to setfacl
group::rw-
other::r--
------------------
but we should prohibit it that user2 changing user1's acl.
In fact, on ext3 and other fs, a message occurs:
setfacl: aaa: Operation not permitted

This patch fixed it.

Signed-off-by: Shi Weihua <shiwh@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
fs/btrfs/acl.c | 3 +++
1 file changed, 3 insertions(+)

--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -157,6 +157,9 @@ static int btrfs_xattr_set_acl(struct in
int ret = 0;
struct posix_acl *acl = NULL;

+ if (!is_owner_or_cap(inode))
+ return -EPERM;
+
if (value) {
acl = posix_acl_from_xattr(value, size);
if (acl == NULL) {