Re: [syzbot] [pm?] WARNING in thermal_thresholds_flush

[Aleksandr Nogikh]

Hi Jann,

On Fri, Oct 18, 2024 at 5:43 PM 'Jann Horn' via syzkaller-bugs
<syzkaller-bugs@xxxxxxxxxxxxxxxx> wrote:
>
> On Fri, Oct 18, 2024 at 3:21 PM syzbot
> <syzbot+f24dd060c1911fe54c85@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > syzbot has bisected this issue to:
> >
> > commit b8c8ba73c68bb3c3e9dad22f488b86c540c839f9
> > Author: Jann Horn <jannh@xxxxxxxxxx>
> > Date:   Fri Aug 9 15:36:56 2024 +0000
> >
> >     slub: Introduce CONFIG_SLUB_RCU_DEBUG
> >
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=14cc4c5f980000
> > start commit:   15e7d45e786a Add linux-next specific files for 20241016
> > git tree:       linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=12cc4c5f980000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=c36416f1c54640c0
> > dashboard link: https://syzkaller.appspot.com/bug?extid=f24dd060c1911fe54c85
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1192f887980000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1417e830580000
> >
> > Reported-by: syzbot+f24dd060c1911fe54c85@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Fixes: b8c8ba73c68b ("slub: Introduce CONFIG_SLUB_RCU_DEBUG")
> >
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>
> This looks like a bogus bisection - the blamed commit was already in
> v6.12-rc1, while the file that contains this warning
> (drivers/thermal/thermal_thresholds.c) doesn't even exist in mainline
> yet.
>

Indeed, the bisection result is wrong :( At one of the steps, syzbot
has hit too many random "lost connection to test machine" crashes,
which derailed the process.

I've filed https://github.com/google/syzkaller/issues/5414. Once
implemented, that should get rid of this class of false positives.

-- 
Aleksandr