Re: [PATCH v3] loop: Fix NULL pointer dereference in lo_rw_aio()

[Hillf Danton]

On Tue, 26 May 2026 22:00:49 -0500 Ming Lei wrote:
>On Wed, May 27, 2026 at 10:35:56AM +0900, Tetsuo Handa wrote:
>> On 2026/05/27 10:20, Ming Lei wrote:
>> >> Of course we should try to figure out the root cause first, but how can we do?
>> > 
>> > Definitely unexpected write IO(after umount & loop closed) from btrfs is more serious,
>> > which may cause data loss, so CC btrfs list and maintainer.
>> 
>> Why do you assume that the culprit is btrfs?
>> 
>> https://syzkaller.appspot.com/bug?extid=bc273027d5643e48e5b3 indicated that
>> this similar race is also happening with jfs.
>
> I just didn't see the above report on jfs.
> 
> It doesn't change anything, the same question still stands: unexpected write IO is issued
> or crosses umount & last closing of loop disk.
>
Given the loop workqueue that triggered the jfs warning, can you specify
the reason why the workqueue in question is NOT flushed while closing disk?