[syzbot] general protection fault in pm_qos_update_target

[Dmitry Vyukov]

On Wed, 20 Apr 2022 at 23:28, syzbot
<syzbot+f7d9295d2565ee819d21 at syzkaller.appspotmail.com> wrote:
>
> syzbot suspects this issue was fixed by commit:
>
> commit 3c3201f8c7bb77eb53b08a3ca8d9a4ddc500b4c0
> Author: Takashi Iwai <tiwai at suse.de>
> Date:   Tue Mar 22 17:07:19 2022 +0000
>
>     ALSA: pcm: Fix races among concurrent prepare and hw_params/hw_free calls
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=104e3034f00000
> start commit:   dbb5afad100a ptrace: make ptrace() fail if the tracee chan..
> git tree:       upstream
> kernel config:  https://syzkaller.appspot.com/x/.config?x=91ff0467ce169bc
> dashboard link: https://syzkaller.appspot.com/bug?extid=f7d9295d2565ee819d21
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16c75e73d00000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: ALSA: pcm: Fix races among concurrent prepare and hw_params/hw_free calls
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection


Looks legit, that code is in the stack trace:

#syz fix:
ALSA: pcm: Fix races among concurrent prepare and hw_params/hw_free calls