Btrfs: should add a permission check for setfacl
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>
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 6ef7b26..6b4d0cc 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -160,6 +160,9 @@
int ret;
struct posix_acl *acl = NULL;
+ if (!is_owner_or_cap(dentry->d_inode))
+ return -EPERM;
+
if (value) {
acl = posix_acl_from_xattr(value, size);
if (acl == NULL) {