CIFS: Fix a possible memory corruption in push locks

If maxBuf is not 0 but less than a size of SMB2 lock structure we can end up with a memory corruption. Cc: Stable <[email protected]> Signed-off-by: Pavel Shilovsky <[email protected]>
redbrain17 · Dec 5, 2016 · e3d240e · e3d240e
1 parent 4772c79
commit e3d240e
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c
@@ -260,7 +260,7 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 	 * and check it for zero before using.
 	 */
 	max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
-	if (!max_buf) {
+	if (max_buf < sizeof(struct smb2_lock_element)) {
 		free_xid(xid);
 		return -EINVAL;
 	}