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 11718C433EF for ; Mon, 10 Jan 2022 11:50:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245057AbiAJLua (ORCPT ); Mon, 10 Jan 2022 06:50:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245016AbiAJLtQ (ORCPT ); Mon, 10 Jan 2022 06:49:16 -0500 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2CBB0C061748; Mon, 10 Jan 2022 03:49:16 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1n6tAQ-0007FN-Bf; Mon, 10 Jan 2022 12:48:50 +0100 Date: Mon, 10 Jan 2022 12:48:50 +0100 From: Florian Westphal To: syzbot Cc: a@unstable.cc, alobakin@pm.me, andrii@kernel.org, ast@kernel.org, atenart@kernel.org, b.a.t.m.a.n@lists.open-mesh.org, bpf@vger.kernel.org, coreteam@netfilter.org, daniel@iogearbox.net, davem@davemloft.net, fw@strlen.de, john.fastabend@gmail.com, jonathan.lemon@gmail.com, kadlec@netfilter.org, kafai@fb.com, kpsingh@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, lukas@wunner.de, mareklindner@neomailbox.ch, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, pablo@netfilter.org, songliubraving@fb.com, sven@narfation.org, sw@simonwunderlich.de, syzkaller-bugs@googlegroups.com, yhs@fb.com Subject: Re: [syzbot] WARNING: suspicious RCU usage in __dev_queue_xmit Message-ID: <20220110114850.GD317@breakpoint.cc> References: <000000000000ca1d2005d537ebac@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000ca1d2005d537ebac@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 4c375272fb0b Merge branch 'net-add-preliminary-netdev-refc.. > git tree: net-next > console output: https://syzkaller.appspot.com/x/log.txt?x=164749a9b00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=2b8e24e3a80e3875 > dashboard link: https://syzkaller.appspot.com/bug?extid=e163f2ff7c3f7efd8203 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11493641b00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11ac6aceb00000 > include/linux/netfilter_netdev.h:97 suspicious rcu_dereference_check() usage! #syz fix: netfilter: egress: avoid a lockdep splat