On 02/22/2019 09:57 AM, Eric Biggers wrote:
> ->setattr() is called under inode_lock(), which __sock_release() also takes.
> So
> the uses of sock->sk are serialized. See commit 6d8c50dcb029 ("socket: close
> race condition between sock_close() and sockfs_setattr()").
Oh right, we added another inode_lock()/inode_unlock() for sock_close()
>
> The issue now is that if ->setattr() happens *after* __sock_release() (which
> is
> possible if fchownat() gets the reference to the file's 'struct path', then
> the
> file is close()d by another thread, then fchownat() continues), it will see
> stale sock->sk because for many socket types it wasn't set to NULL earlier.
>
> - Eric
>
