--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1550,7 +1550,7 @@ static int do_loopback(struct path *path
 	if (!mnt)
 		goto out;
 
-	err = check_union_mnt(&old_path, mnt, mnt_flags);
+	err = check_union_mnt(path, mnt, mnt_flags);
 	if (err)
 		goto out;