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=-8.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 1BBB9C31E50 for ; Mon, 17 Jun 2019 14:14:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F29D7206B7 for ; Mon, 17 Jun 2019 14:14:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727949AbfFQOON (ORCPT ); Mon, 17 Jun 2019 10:14:13 -0400 Received: from Chamillionaire.breakpoint.cc ([193.142.43.52]:44730 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725906AbfFQOOM (ORCPT ); Mon, 17 Jun 2019 10:14:12 -0400 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.89) (envelope-from ) id 1hcsOe-0005vF-9s; Mon, 17 Jun 2019 16:14:09 +0200 From: Florian Westphal To: Cc: tariqt@mellanox.com, ranro@mellanox.com, maorg@mellanox.com, edumazet@google.com, Florian Westphal Subject: [PATCH net-next 1/2] net: ipv4: remove erroneous advancement of list pointer Date: Mon, 17 Jun 2019 16:02:27 +0200 Message-Id: <20190617140228.12523-2-fw@strlen.de> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190617140228.12523-1-fw@strlen.de> References: <20190617140228.12523-1-fw@strlen.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Causes crash when lifetime expires on an adress as garbage is dereferenced soon after. This used to look like this: for (ifap = &ifa->ifa_dev->ifa_list; *ifap != NULL; ifap = &(*ifap)->ifa_next) { if (*ifap == ifa) ... but this was changed to: struct in_ifaddr *tmp; ifap = &ifa->ifa_dev->ifa_list; tmp = rtnl_dereference(*ifap); while (tmp) { tmp = rtnl_dereference(tmp->ifa_next); // Bogus if (rtnl_dereference(*ifap) == ifa) { ... ifap = &tmp->ifa_next; // Can be NULL tmp = rtnl_dereference(*ifap); // Dereference } } Remove the bogus assigment/list entry skip. Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list") Signed-off-by: Florian Westphal --- net/ipv4/devinet.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 925dffa915cb..914ccc7f192a 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -745,8 +745,7 @@ static void check_lifetime(struct work_struct *work) ifap = &ifa->ifa_dev->ifa_list; tmp = rtnl_dereference(*ifap); while (tmp) { - tmp = rtnl_dereference(tmp->ifa_next); - if (rtnl_dereference(*ifap) == ifa) { + if (tmp == ifa) { inet_del_ifa(ifa->ifa_dev, ifap, 1); break; -- 2.21.0