Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <F17EC83C-9D70-463A-9C46-FBCC53A1F13C.ref@yahoo.com>
 <F17EC83C-9D70-463A-9C46-FBCC53A1F13C@yahoo.com> <20230705043955.GE15522@pengutronix.de>
In-Reply-To: <20230705043955.GE15522@pengutronix.de>
From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Wed, 5 Jul 2023 06:50:43 +0200
Message-ID: <CACT4Y+bGjJjmMNMQZEZFTh8UnyXNYSTy97SxtuKaJ96XkALkWw@mail.gmail.com>
Subject: Re: [PATCH] can: j1939: prevent deadlock by changing j1939_socks_lock
 to rwlock
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     Astra Joan <astrajoan@yahoo.com>, davem@davemloft.net,
        edumazet@google.com, ivan.orlov0322@gmail.com,
        kernel@pengutronix.de, kuba@kernel.org, linux-can@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux@rempel-privat.de,
        mkl@pengutronix.de, netdev@vger.kernel.org, pabeni@redhat.com,
        robin@protonic.nl, skhan@linuxfoundation.org,
        socketcan@hartkopp.net,
        syzbot+1591462f226d9cbf0564@syzkaller.appspotmail.com,
        syzkaller-bugs@googlegroups.com,
        syzkaller <syzkaller@googlegroups.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, 5 Jul 2023 at 06:40, Oleksij Rempel <o.rempel@pengutronix.de> wrote:
>
> On Tue, Jul 04, 2023 at 10:55:47AM -0700, Astra Joan wrote:
> > Hi Oleksij,
> >
> > Thank you for providing help with the bug fix! The patch was created
> > when I was working on another bug:
> >
> > https://syzkaller.appspot.com/bug?extid=881d65229ca4f9ae8c84
> >
> > But the patch was not a direct fix of the problem reported in the
> > unregister_netdevice function call. Instead, it suppresses potential
> > deadlock information to guarantee the real bug would show up. Since I
> > have verified that the patch resolved a deadlock situation involving
> > the exact same locks, I'm pretty confident it would be a proper fix for
> > the current bug in this thread.
> >
> > I'm not sure, though, about how I could instruct Syzbot to create a
> > reproducer to properly test this patch. Could you or anyone here help
> > me find the next step? Thank you so much!
>
> Sorry, I'm not syzbot expert. I hope someone else can help here.

+syzkaller mailing list

Hi Astra,

You mean you have a reproducer and you want syzbot to run it with your patch?
No such feature exists at the moment.

Presumably you already run it locally, so I am not sure syzbot can add
much value here.