diff mbox series

ksmbd: fix reference count leak in smb_check_perm_dacl()

Message ID 20220429081121.1640-1-xiongx18@fudan.edu.cn (mailing list archive)
State New, archived
Headers show
Series ksmbd: fix reference count leak in smb_check_perm_dacl() | expand

Commit Message

Xin Xiong April 29, 2022, 8:11 a.m. UTC 
The issue happens in a specific path in smb_check_perm_dacl(). When
"id" and "uid" have the same value, the function simply jumps out of
the loop without decrementing the reference count of the object
"posix_acls", which is increased by get_acl() earlier. This may
result in memory leaks.

Fix it by decreasing the reference count of "posix_acls" before
jumping to label "check_access_bits".

Fixes: 777cad1604d6 ("ksmbd: remove select FS_POSIX_ACL in Kconfig")
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
 fs/ksmbd/smbacl.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Namjae Jeon April 30, 2022, 4:14 a.m. UTC | #1 
2022-04-29 17:11 GMT+09:00, Xin Xiong <xiongx18@fudan.edu.cn>:
> The issue happens in a specific path in smb_check_perm_dacl(). When
> "id" and "uid" have the same value, the function simply jumps out of
> the loop without decrementing the reference count of the object
> "posix_acls", which is increased by get_acl() earlier. This may
> result in memory leaks.
>
> Fix it by decreasing the reference count of "posix_acls" before
> jumping to label "check_access_bits".
>
> Fixes: 777cad1604d6 ("ksmbd: remove select FS_POSIX_ACL in Kconfig")
> Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>

Thanks!
diff mbox series

Patch

diff --git a/fs/ksmbd/smbacl.c b/fs/ksmbd/smbacl.c
index 6ecf55ea1fed..38f23bf981ac 100644
--- a/fs/ksmbd/smbacl.c
+++ b/fs/ksmbd/smbacl.c
@@ -1261,6 +1261,7 @@  int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
 					if (!access_bits)
 						access_bits =
 							SET_MINIMUM_RIGHTS;
+					posix_acl_release(posix_acls);
 					goto check_access_bits;
 				}
 			}