Re: INFO: task hung in io_uring_flush

[Pavel Begunkov]

On 10/08/2020 19:04, syzbot wrote:
> syzbot has bisected this issue to:
> 
> commit f86cd20c9454847a524ddbdcdec32c0380ed7c9b
> Author: Jens Axboe <axboe@xxxxxxxxx>
> Date:   Wed Jan 29 20:46:44 2020 +0000
> 
>     io_uring: fix linked command file table usage

There are several known problems with io_uring_cancel_files() including
races and hangs. I had some drafts and going to patch it in a week or so.

> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16db4d3a900000
> start commit:   9420f1ce Merge tag 'pinctrl-v5.9-1' of git://git.kernel.or..
> git tree:       upstream
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=15db4d3a900000
> console output: https://syzkaller.appspot.com/x/log.txt?x=11db4d3a900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=72cf85e4237850c8
> dashboard link: https://syzkaller.appspot.com/bug?extid=6338dcebf269a590b668
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=141dde52900000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15b196aa900000
> 
> Reported-by: syzbot+6338dcebf269a590b668@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: f86cd20c9454 ("io_uring: fix linked command file table usage")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 

-- 
Pavel Begunkov