Re: BUG: unable to handle kernel paging request in io_wq_cancel_all

[Dmitry Vyukov]

On Fri, Nov 1, 2019 at 6:56 PM Jens Axboe <axboe@xxxxxxxxx> wrote:
>
> On 11/1/19 11:50 AM, Dmitry Vyukov wrote:
> > On Wed, Oct 30, 2019 at 3:41 PM Jens Axboe <axboe@xxxxxxxxx> wrote:
> >>
> >> On 10/30/19 1:44 AM, syzbot wrote:
> >>> syzbot has bisected this bug to:
> >>>
> >>> commit ef0524d3654628ead811f328af0a4a2953a8310f
> >>> Author: Jens Axboe <axboe@xxxxxxxxx>
> >>> Date:   Thu Oct 24 13:25:42 2019 +0000
> >>>
> >>>        io_uring: replace workqueue usage with io-wq
> >>>
> >>> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16acf5d0e00000
> >>> start commit:   c57cf383 Add linux-next specific files for 20191029
> >>> git tree:       linux-next
> >>> final crash:    https://syzkaller.appspot.com/x/report.txt?x=15acf5d0e00000
> >>> console output: https://syzkaller.appspot.com/x/log.txt?x=11acf5d0e00000
> >>> kernel config:  https://syzkaller.appspot.com/x/.config?x=cb86688f30db053d
> >>> dashboard link: https://syzkaller.appspot.com/bug?extid=221cc24572a2fed23b6b
> >>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=168671d4e00000
> >>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=140f4898e00000
> >>>
> >>> Reported-by: syzbot+221cc24572a2fed23b6b@xxxxxxxxxxxxxxxxxxxxxxxxx
> >>> Fixes: ef0524d36546 ("io_uring: replace workqueue usage with io-wq")
> >>
> >> Good catch, it's a case of NULL vs ERR_PTR() confusion. I'll fold in
> >> the below fix.
> >
> > Hi Jens,
> >
> > Please either add the syzbot tag to commit, or close manually with
> > "#syz fix" (though requires waiting until the fixed commit is in
> > linux-next).
> > See https://goo.gl/tpsmEJ#rebuilt-treesamended-patches for details.
> > Otherwise, the bug will be considered open and will waste time of
> > humans looking at open bugs and prevent syzbot from reporting new bugs
> > in io_uring.
>
> It's queued up since two days ago:
>
> http://git.kernel.dk/cgit/linux-block/commit/?h=for-5.5/io_uring&id=975c99a570967dd48e917dd7853867fee3febabd
>
> and should have the right attributions, so hopefully it'll catch up
> eventually.
>
> --
> Jens Axboe
>

Cool! Thanks!
I've seen "fold in" and historically lots of developers did not add
the tag during amending, so wanted to double check.