From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A458AC001DB for ; Wed, 5 Jul 2023 04:40:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230157AbjGEEkU (ORCPT ); Wed, 5 Jul 2023 00:40:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229576AbjGEEkQ (ORCPT ); Wed, 5 Jul 2023 00:40:16 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4A2C10FB for ; Tue, 4 Jul 2023 21:40:15 -0700 (PDT) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qGuJ5-0005TM-7p; Wed, 05 Jul 2023 06:39:59 +0200 Received: from ore by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1qGuJ1-000542-U6; Wed, 05 Jul 2023 06:39:55 +0200 Date: Wed, 5 Jul 2023 06:39:55 +0200 From: Oleksij Rempel To: Astra Joan Cc: 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 Subject: Re: [PATCH] can: j1939: prevent deadlock by changing j1939_socks_lock to rwlock Message-ID: <20230705043955.GE15522@pengutronix.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |