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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A089C43387 for ; Mon, 17 Dec 2018 23:18:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 39AA9214C6 for ; Mon, 17 Dec 2018 23:18:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726928AbeLQXSi (ORCPT ); Mon, 17 Dec 2018 18:18:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33798 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726738AbeLQXSh (ORCPT ); Mon, 17 Dec 2018 18:18:37 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 06CFE89AD3; Mon, 17 Dec 2018 23:18:37 +0000 (UTC) Received: from localhost (ovpn-200-20.brq.redhat.com [10.40.200.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6C5A619741; Mon, 17 Dec 2018 23:18:33 +0000 (UTC) Date: Tue, 18 Dec 2018 00:18:28 +0100 From: Stefano Brivio To: Dmitry Vyukov Cc: Eric Dumazet , Arjan van de Ven , "Paul E. McKenney" , syzbot , Andrew Morton , Josh Triplett , LKML , Ingo Molnar , syzkaller-bugs , netdev Subject: Re: WARNING in __rcu_read_unlock Message-ID: <20181218001828.49cea463@redhat.com> In-Reply-To: References: <0000000000005e47a2057d0edc49@google.com> <20181216190412.GE4170@linux.ibm.com> <20181217112916.GG4170@linux.ibm.com> <1583d5fc-34bf-3a81-363d-01a1085a7363@linux.intel.com> <20641819-e4fb-f3bd-34c8-c68106cccd0e@gmail.com> <20181217162421.6d636ee5@redhat.com> Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 17 Dec 2018 23:18:37 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 17 Dec 2018 16:53:36 +0100 Dmitry Vyukov wrote: > On Mon, Dec 17, 2018 at 4:24 PM Stefano Brivio wrote: > > > > On Mon, 17 Dec 2018 06:57:35 -0800 > > Eric Dumazet wrote: > > > > > Might be cause by commit b8a51b38e4d4dec3e379d52c0fe1a66827f7cf1e > > > fou, fou6: ICMP error handlers for FoU and GUE > > > > This: > > > > diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c > > index 0d0ad19ecb87..20a6de26d146 100644 > > --- a/net/ipv4/fou.c > > +++ b/net/ipv4/fou.c > > @@ -1008,6 +1008,9 @@ static int gue_err_proto_handler(int proto, struct sk_buff *skb, u32 info) > > { > > const struct net_protocol *ipprot = rcu_dereference(inet_protos[proto]); > > > > + if (ipprot == IPPROTO_UDP) > > + return -EINVAL; > > + > > if (ipprot && ipprot->err_handler) { > > if (!ipprot->err_handler(skb, info)) > > return 0; > > > > should fix the issue, but I still have to run tests and make sure we > > don't hit similar cases. > > Please don't forget to add a regression test for it too ;) Where would you suggest to add this? The only selftest that goes through this path currently is net/pmtu.sh, but as configuration of an actual UDP-in-GUE tunnel is currently not supported, I would really need to forge that specific packet, so that doesn't seem to be a good fit. Won't syzbot add this to some list of reproducers that are checked in the future? -- Stefano