Re: WARNING in up_write

From: Matthew Wilcox
Date: Wed Apr 04 2018 - 23:25:02 EST


On Wed, Apr 04, 2018 at 11:22:00PM -0400, Theodore Y. Ts'o wrote:
> On Wed, Apr 04, 2018 at 12:35:04PM -0700, Matthew Wilcox wrote:
> > On Wed, Apr 04, 2018 at 09:24:05PM +0200, Dmitry Vyukov wrote:
> > > On Tue, Apr 3, 2018 at 4:01 AM, syzbot
> > > <syzbot+dc5ab2babdf22ca091af@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > > > DEBUG_LOCKS_WARN_ON(sem->owner != get_current())
> > > > WARNING: CPU: 1 PID: 4441 at kernel/locking/rwsem.c:133 up_write+0x1cc/0x210
> > > > kernel/locking/rwsem.c:133
> > > > Kernel panic - not syncing: panic_on_warn set ...
> >
> > Message-Id: <1522852646-2196-1-git-send-email-longman@xxxxxxxxxx>
> >
>
> We were way ahead of syzbot in this case. :-)

Not really ... syzbot caught it Monday evening ;-)

Date: Mon, 02 Apr 2018 19:01:01 -0700
From: syzbot <syzbot+dc5ab2babdf22ca091af@xxxxxxxxxxxxxxxxxxxxxxxxx>
To: linux-fsdevel@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx,
syzkaller-bugs@xxxxxxxxxxxxxxxx, viro@xxxxxxxxxxxxxxxxxx
Subject: WARNING in up_write