Re: [syzbot] [integrity] [overlayfs] possible deadlock in mnt_want_write (2)

From: Amir Goldstein
Date: Thu Oct 05 2023 - 12:16:59 EST


On Wed, Oct 4, 2023 at 7:45 PM syzbot
<syzbot+b42fe626038981fb7bfa@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> syzbot has bisected this issue to:
>
> commit 708fa01597fa002599756bf56a96d0de1677375c
> Author: Miklos Szeredi <mszeredi@xxxxxxxxxx>
> Date: Mon Apr 12 10:00:37 2021 +0000
>
> ovl: allow upperdir inside lowerdir
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17ad11b2680000
> start commit: 3aba70aed91f Merge tag 'gpio-fixes-for-v6.6-rc3' of git://..
> git tree: upstream
> final oops: https://syzkaller.appspot.com/x/report.txt?x=146d11b2680000
> console output: https://syzkaller.appspot.com/x/log.txt?x=106d11b2680000
> kernel config: https://syzkaller.appspot.com/x/.config?x=e4ca82a1bedd37e4
> dashboard link: https://syzkaller.appspot.com/bug?extid=b42fe626038981fb7bfa
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1304fba6680000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13cec0dc680000
>
> Reported-by: syzbot+b42fe626038981fb7bfa@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 708fa01597fa ("ovl: allow upperdir inside lowerdir")
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

#syz test: https://github.com/amir73il/linux ima-ovl-fix