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 DECC3C433F5 for ; Tue, 17 May 2022 19:48:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236180AbiEQTsB (ORCPT ); Tue, 17 May 2022 15:48:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233185AbiEQTsA (ORCPT ); Tue, 17 May 2022 15:48:00 -0400 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5663137BDC; Tue, 17 May 2022 12:47:58 -0700 (PDT) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1nr3Ad-0003Z8-52; Tue, 17 May 2022 21:47:51 +0200 Date: Tue, 17 May 2022 21:47:51 +0200 From: Florian Westphal To: syzbot Cc: ali.abdallah@suse.com, coreteam@netfilter.org, davem@davemloft.net, edumazet@google.com, fw@strlen.de, kadlec@netfilter.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, ozsh@nvidia.com, pabeni@redhat.com, pablo@netfilter.org, paulb@nvidia.com, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] KASAN: use-after-free Read in nf_confirm Message-ID: <20220517194751.GA4316@breakpoint.cc> References: <000000000000fb4af305df391431@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000fb4af305df391431@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: d887ae3247e0 octeontx2-pf: Remove unnecessary synchronize_.. > git tree: net-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=17f2b659f00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=b1aab282dc5dd920 > dashboard link: https://syzkaller.appspot.com/bug?extid=793a590957d9c1b96620 > 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=1313dce6f00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=169eb59ef00000 > > The issue was bisected to: > > commit 1397af5bfd7d32b0cf2adb70a78c9a9e8f11d912 > Author: Florian Westphal > Date: Mon Apr 11 11:01:18 2022 +0000 > > netfilter: conntrack: remove the percpu dying list AFAICS this bug exists since Fixes: 71d8c47fc653 ("netfilter: conntrack: introduce clash resolution on insertion race") nf_confirm needs to re-fetch 'ct' from skb->_nfct. Will send a patch.