Re: INFO: rcu detected stall in snd_pcm_oss_write3 (2)

From: Dmitry Vyukov
Date: Sat Apr 07 2018 - 07:59:17 EST


#syz dup: INFO: rcu detected stall in io_playback_transfer

On Sat, Apr 7, 2018 at 1:00 PM, Takashi Iwai <tiwai@xxxxxxx> wrote:
> On Sat, 07 Apr 2018 12:19:33 +0200,
> Dmitry Vyukov wrote:
>>
>> On Sat, Apr 7, 2018 at 11:56 AM, Takashi Iwai <tiwai@xxxxxxx> wrote:
>> > On Fri, 06 Apr 2018 23:14:01 +0200,
>> > syzbot wrote:
>> >>
>> >> syzbot has found reproducer for the following crash on upstream commit
>> >> 38c23685b273cfb4ccf31a199feccce3bdcb5d83 (Fri Apr 6 04:29:35 2018 +0000)
>> >> Merge tag 'armsoc-drivers' of
>> >> git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
>> >> syzbot dashboard link:
>> >> https://syzkaller.appspot.com/bug?extid=150189c103427d31a053
>> >>
>> >> So far this crash happened 15 times on upstream.
>> >> C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5405588854931456
>> >> syzkaller reproducer:
>> >> https://syzkaller.appspot.com/x/repro.syz?id=5561439796330496
>> >> Raw console output:
>> >> https://syzkaller.appspot.com/x/log.txt?id=5697900571000832
>> >> Kernel config:
>> >> https://syzkaller.appspot.com/x/.config?id=-5813481738265533882
>> >> compiler: gcc (GCC) 8.0.1 20180301 (experimental)
>> >
>> > Thanks to the reproducer, I could spot out now.
>> > Below is the patch (which was submitted as well).
>>
>> Great!
>>
>> There are 3 more recent stalls in sound, does this fix them as well?
>>
>> https://groups.google.com/forum/#!msg/syzkaller-bugs/MGfk8WH3O6k/ja2xKpdcCAAJ
>> https://groups.google.com/forum/#!msg/syzkaller-bugs/74HglwU94go/T89ohzlYCAAJ
>> https://groups.google.com/forum/#!msg/syzkaller-bugs/D2xWV7WTRDk/5y2kZyBICAAJ
>
> Yes, very likely.
>
>
> Takashi