Re: possible deadlock in console_trylock_spinning

From: Tetsuo Handa
Date: Tue Jun 25 2019 - 05:53:48 EST


On 2019/06/25 17:55, syzbot wrote:
> syzbot has bisected this bug to:
>
> commit e80b18599a39a625bc8b2e39ba3004a62f78805a
> Author: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Date: Fri Apr 12 11:04:54 2019 +0000
>
> tomoyo: Add a kernel config option for fuzzing testing.
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=156e43cea00000
> start commit: abf02e29 Merge tag 'pm-5.2-rc6' of git://git.kernel.org/pu..
> git tree: upstream
> final crash: https://syzkaller.appspot.com/x/report.txt?x=176e43cea00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=136e43cea00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=28ec3437a5394ee0
> dashboard link: https://syzkaller.appspot.com/bug?extid=fc1da0f1a577d15b64fc
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1357add6a00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1611ac89a00000
>
> Reported-by: syzbot+fc1da0f1a577d15b64fc@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: e80b18599a39 ("tomoyo: Add a kernel config option for fuzzing testing.")
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>

This is not a TOMOYO's problem because that commit simply confused inject_fault(4)
by adding memory allocation from TOMOYO's hook. Anyway, this bug should be sent to
printk() people.