Re: BUG: using __this_cpu_read() in preemptible code in trace_hardirqs_on

[Dmitry Vyukov]

On Fri, Oct 16, 2020 at 10:33 PM syzbot
<syzbot+53f8ce8bbc07924b6417@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> syzbot has bisected this issue to:
>
> commit 4d004099a668c41522242aa146a38cc4eb59cb1e
> Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Date:   Fri Oct 2 09:04:21 2020 +0000
>
>     lockdep: Fix lockdep recursion
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=174a766f900000
> start commit:   9ff9b0d3 Merge tag 'net-next-5.10' of git://git.kernel.org..
> git tree:       net-next
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=14ca766f900000
> console output: https://syzkaller.appspot.com/x/log.txt?x=10ca766f900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d13c3fa80bc4bcc1
> dashboard link: https://syzkaller.appspot.com/bug?extid=53f8ce8bbc07924b6417
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15b63310500000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1565657f900000
>
> Reported-by: syzbot+53f8ce8bbc07924b6417@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 4d004099a668 ("lockdep: Fix lockdep recursion")
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection


This is now one of top crashers with 190K crashes in the past 12 days:
https://syzkaller.appspot.com/bug?id=e7cbd9d7047a1c4e14bbdc194a7d87de1f168289
This is now almost the only bug syzbot triggers.