linux-block.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* Re: BUG: unable to handle kernel paging request in io_wq_cancel_all
       [not found] <000000000000c6fb2a05961a0dd8@google.com>
@ 2019-10-30  7:44 ` syzbot
  2019-10-30 14:41   ` Jens Axboe
  0 siblings, 1 reply; 6+ messages in thread
From: syzbot @ 2019-10-30  7:44 UTC (permalink / raw)
  To: akpm, axboe, dan.j.williams, dhowells, gregkh, hannes, joel,
	linux-block, linux-fsdevel, linux-kernel, mchehab+samsung, mingo,
	patrick.bellasi, rgb, rostedt, syzkaller-bugs, viro,
	yamada.masahiro

syzbot has bisected this bug to:

commit ef0524d3654628ead811f328af0a4a2953a8310f
Author: Jens Axboe <axboe@kernel.dk>
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@syzkaller.appspotmail.com
Fixes: ef0524d36546 ("io_uring: replace workqueue usage with io-wq")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: BUG: unable to handle kernel paging request in io_wq_cancel_all
  2019-10-30  7:44 ` BUG: unable to handle kernel paging request in io_wq_cancel_all syzbot
@ 2019-10-30 14:41   ` Jens Axboe
  2019-11-01 17:50     ` Dmitry Vyukov
  0 siblings, 1 reply; 6+ messages in thread
From: Jens Axboe @ 2019-10-30 14:41 UTC (permalink / raw)
  To: syzbot, akpm, dan.j.williams, dhowells, gregkh, hannes, joel,
	linux-block, linux-fsdevel, linux-kernel, mchehab+samsung, mingo,
	patrick.bellasi, rgb, rostedt, syzkaller-bugs, viro,
	yamada.masahiro

On 10/30/19 1:44 AM, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit ef0524d3654628ead811f328af0a4a2953a8310f
> Author: Jens Axboe <axboe@kernel.dk>
> 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@syzkaller.appspotmail.com
> 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.


diff --git a/fs/io_uring.c b/fs/io_uring.c
index af1937d66aee..76d653085987 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3534,8 +3534,9 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
 	/* Do QD, or 4 * CPUS, whatever is smallest */
 	concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
 	ctx->io_wq = io_wq_create(concurrency, ctx->sqo_mm);
-	if (!ctx->io_wq) {
-		ret = -ENOMEM;
+	if (IS_ERR(ctx->io_wq)) {
+		ret = PTR_ERR(ctx->io_wq);
+		ctx->io_wq = NULL;
 		goto err;
 	}
 

-- 
Jens Axboe


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: BUG: unable to handle kernel paging request in io_wq_cancel_all
  2019-10-30 14:41   ` Jens Axboe
@ 2019-11-01 17:50     ` Dmitry Vyukov
  2019-11-01 17:56       ` Jens Axboe
  0 siblings, 1 reply; 6+ messages in thread
From: Dmitry Vyukov @ 2019-11-01 17:50 UTC (permalink / raw)
  To: Jens Axboe
  Cc: syzbot, Andrew Morton, Dan Williams, David Howells,
	Greg Kroah-Hartman, Johannes Weiner, Joel Fernandes, linux-block,
	linux-fsdevel, LKML, mchehab+samsung, Ingo Molnar,
	patrick.bellasi, Richard Guy Briggs, Steven Rostedt,
	syzkaller-bugs, Al Viro, Masahiro Yamada

On Wed, Oct 30, 2019 at 3:41 PM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 10/30/19 1:44 AM, syzbot wrote:
> > syzbot has bisected this bug to:
> >
> > commit ef0524d3654628ead811f328af0a4a2953a8310f
> > Author: Jens Axboe <axboe@kernel.dk>
> > 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@syzkaller.appspotmail.com
> > 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.

> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index af1937d66aee..76d653085987 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -3534,8 +3534,9 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
>         /* Do QD, or 4 * CPUS, whatever is smallest */
>         concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
>         ctx->io_wq = io_wq_create(concurrency, ctx->sqo_mm);
> -       if (!ctx->io_wq) {
> -               ret = -ENOMEM;
> +       if (IS_ERR(ctx->io_wq)) {
> +               ret = PTR_ERR(ctx->io_wq);
> +               ctx->io_wq = NULL;
>                 goto err;
>         }
>
>
> --
> Jens Axboe
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0e2bc2bf-2a7a-73c5-03e2-9d08f89f0ffa%40kernel.dk.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: BUG: unable to handle kernel paging request in io_wq_cancel_all
  2019-11-01 17:50     ` Dmitry Vyukov
@ 2019-11-01 17:56       ` Jens Axboe
  2019-11-01 18:03         ` Dmitry Vyukov
  0 siblings, 1 reply; 6+ messages in thread
From: Jens Axboe @ 2019-11-01 17:56 UTC (permalink / raw)
  To: Dmitry Vyukov
  Cc: syzbot, Andrew Morton, Dan Williams, David Howells,
	Greg Kroah-Hartman, Johannes Weiner, Joel Fernandes, linux-block,
	linux-fsdevel, LKML, mchehab+samsung, Ingo Molnar,
	patrick.bellasi, Richard Guy Briggs, Steven Rostedt,
	syzkaller-bugs, Al Viro, Masahiro Yamada

On 11/1/19 11:50 AM, Dmitry Vyukov wrote:
> On Wed, Oct 30, 2019 at 3:41 PM Jens Axboe <axboe@kernel.dk> wrote:
>>
>> On 10/30/19 1:44 AM, syzbot wrote:
>>> syzbot has bisected this bug to:
>>>
>>> commit ef0524d3654628ead811f328af0a4a2953a8310f
>>> Author: Jens Axboe <axboe@kernel.dk>
>>> 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@syzkaller.appspotmail.com
>>> 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


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: BUG: unable to handle kernel paging request in io_wq_cancel_all
  2019-11-01 17:56       ` Jens Axboe
@ 2019-11-01 18:03         ` Dmitry Vyukov
  2019-11-01 18:07           ` Jens Axboe
  0 siblings, 1 reply; 6+ messages in thread
From: Dmitry Vyukov @ 2019-11-01 18:03 UTC (permalink / raw)
  To: Jens Axboe
  Cc: syzbot, Andrew Morton, Dan Williams, David Howells,
	Greg Kroah-Hartman, Johannes Weiner, Joel Fernandes, linux-block,
	linux-fsdevel, LKML, mchehab+samsung, Ingo Molnar,
	patrick.bellasi, Richard Guy Briggs, Steven Rostedt,
	syzkaller-bugs, Al Viro, Masahiro Yamada

On Fri, Nov 1, 2019 at 6:56 PM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 11/1/19 11:50 AM, Dmitry Vyukov wrote:
> > On Wed, Oct 30, 2019 at 3:41 PM Jens Axboe <axboe@kernel.dk> wrote:
> >>
> >> On 10/30/19 1:44 AM, syzbot wrote:
> >>> syzbot has bisected this bug to:
> >>>
> >>> commit ef0524d3654628ead811f328af0a4a2953a8310f
> >>> Author: Jens Axboe <axboe@kernel.dk>
> >>> 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@syzkaller.appspotmail.com
> >>> 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.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: BUG: unable to handle kernel paging request in io_wq_cancel_all
  2019-11-01 18:03         ` Dmitry Vyukov
@ 2019-11-01 18:07           ` Jens Axboe
  0 siblings, 0 replies; 6+ messages in thread
From: Jens Axboe @ 2019-11-01 18:07 UTC (permalink / raw)
  To: Dmitry Vyukov
  Cc: syzbot, Andrew Morton, Dan Williams, David Howells,
	Greg Kroah-Hartman, Johannes Weiner, Joel Fernandes, linux-block,
	linux-fsdevel, LKML, mchehab+samsung, Ingo Molnar,
	patrick.bellasi, Richard Guy Briggs, Steven Rostedt,
	syzkaller-bugs, Al Viro, Masahiro Yamada

On 11/1/19 12:03 PM, Dmitry Vyukov wrote:
> On Fri, Nov 1, 2019 at 6:56 PM Jens Axboe <axboe@kernel.dk> wrote:
>>
>> On 11/1/19 11:50 AM, Dmitry Vyukov wrote:
>>> On Wed, Oct 30, 2019 at 3:41 PM Jens Axboe <axboe@kernel.dk> wrote:
>>>>
>>>> On 10/30/19 1:44 AM, syzbot wrote:
>>>>> syzbot has bisected this bug to:
>>>>>
>>>>> commit ef0524d3654628ead811f328af0a4a2953a8310f
>>>>> Author: Jens Axboe <axboe@kernel.dk>
>>>>> 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@syzkaller.appspotmail.com
>>>>> 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.

I'm often guilty of that, I think, but for this one I just kept it
separate since I didn't want to rebase things at this point. So I do
appreciate the reminder, I'm sure it'll be pertinent in many other
cases...

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2019-11-01 18:07 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <000000000000c6fb2a05961a0dd8@google.com>
2019-10-30  7:44 ` BUG: unable to handle kernel paging request in io_wq_cancel_all syzbot
2019-10-30 14:41   ` Jens Axboe
2019-11-01 17:50     ` Dmitry Vyukov
2019-11-01 17:56       ` Jens Axboe
2019-11-01 18:03         ` Dmitry Vyukov
2019-11-01 18:07           ` Jens Axboe

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).