Re: [syzbot] [kernfs?] possible deadlock in kernfs_fop_llseek

[Amir Goldstein]

On Thu, Apr 4, 2024 at 9:54 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
>
> On Thu, Apr 4, 2024 at 2:51 AM syzbot
> <syzbot+9a5b0ced8b1bfb238b56@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > syzbot has bisected this issue to:
> >
> > commit 0fedefd4c4e33dd24f726b13b5d7c143e2b483be
> > Author: Valentine Sinitsyn <valesini@xxxxxxxxxxxxxx>
> > Date:   Mon Sep 25 08:40:12 2023 +0000
> >
> >     kernfs: sysfs: support custom llseek method for sysfs entries
> >
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17cb5e03180000
> > start commit:   fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
> > git tree:       upstream
> > final oops:     https://syzkaller.appspot.com/x/report.txt?x=142b5e03180000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=102b5e03180000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=4d90a36f0cab495a
> > dashboard link: https://syzkaller.appspot.com/bug?extid=9a5b0ced8b1bfb238b56
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17f1d93d180000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15c38139180000
> >
> > Reported-by: syzbot+9a5b0ced8b1bfb238b56@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Fixes: 0fedefd4c4e3 ("kernfs: sysfs: support custom llseek method for sysfs entries")
> >
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> >
>

Let's test Al's solution.

#syz test: https://github.com/amir73il/linux/ vfs-fixes

Thanks,
Amir.