[if nobody objects, I'm going to throw that into #fixes and send to Linus
in a couple of days]
Once want_mount_setattr() has returned a positive, it does require
finish_mount_kattr() to release ->mnt_userns. Failing do_mount_setattr()
does not change that.
As the result, we can end up leaking userns and possibly mnt_idmap as
well.
Fixes: c4a16820d901 ("fs: add open_tree_attr()")
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
diff --git a/fs/namespace.c b/fs/namespace.c
index eed83254492f..54c59e091919 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -5307,16 +5307,12 @@ SYSCALL_DEFINE5(open_tree_attr, int, dfd, const char __user *, filename,
kattr.kflags |= MOUNT_KATTR_RECURSE;
ret = wants_mount_setattr(uattr, usize, &kattr);
- if (ret < 0)
- return ret;
-
- if (ret) {
+ if (ret > 0) {
ret = do_mount_setattr(&file->f_path, &kattr);
- if (ret)
- return ret;
-
finish_mount_kattr(&kattr);
}
+ if (ret)
+ return ret;
}
fd = get_unused_fd_flags(flags & O_CLOEXEC);
