From patchwork Wed Jun 11 23:41:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Linus_L=C3=BCssing?= X-Patchwork-Id: 358936 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 7CE451400AB for ; Thu, 12 Jun 2014 09:41:10 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754327AbaFKXkl (ORCPT ); Wed, 11 Jun 2014 19:40:41 -0400 Received: from mout.web.de ([212.227.17.12]:57977 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752671AbaFKXkj (ORCPT ); Wed, 11 Jun 2014 19:40:39 -0400 Received: from localhost ([109.201.143.233]) by smtp.web.de (mrweb101) with ESMTPSA (Nemesis) id 0MFL2m-1X0MIt0JWe-00EKXf; Thu, 12 Jun 2014 01:40:31 +0200 From: =?UTF-8?q?Linus=20L=C3=BCssing?= To: netdev@vger.kernel.org Cc: bridge@lists.linux-foundation.org, Stephen Hemminger , "David S. Miller" , linux-kernel@vger.kernel.org, =?UTF-8?q?Linus=20L=C3=BCssing?= Subject: [PATCH 1/2] bridge: fix smatch warning / potential null pointer dereference Date: Thu, 12 Jun 2014 01:41:23 +0200 Message-Id: <1402530084-15061-2-git-send-email-linus.luessing@web.de> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1402530084-15061-1-git-send-email-linus.luessing@web.de> References: <1402530084-15061-1-git-send-email-linus.luessing@web.de> MIME-Version: 1.0 X-Provags-ID: V03:K0:nWa4PpVVut72Z1Isw10GT8GaTm7RXw3/6cskf5CwcCQMBXzhNii uBVRCgDSCBXqQilUegHh0MKzRT0F4WI743tuzSrOak0Xgoj41Iljlw/pqlqL4b+8VdVYCG8 mcjaSknxmknwvLgUpZGtC4YbHSLlFM4dHaawkJz5DFEwW8apfDeWSBvqx6pUfKp5FPqJj4f Tf+gK3I5oOooDiD+eM+2A== Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org "New smatch warnings: net/bridge/br_multicast.c:1368 br_ip6_multicast_query() error: we previously assumed 'group' could be null (see line 1349)" In the rare (sort of broken) case of a query having a Maximum Response Delay of zero, we could create a potential null pointer dereference. Fixing this by skipping the multicast specific MLD Query parsing again if no multicast group address is available. Introduced by dc4eb53a996a78bfb8ea07b47423ff5a3aadc362 ("bridge: adhere to querier election mechanism specified by RFCs") Reported-by: Dan Carpenter Signed-off-by: Linus Lüssing --- net/bridge/br_multicast.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index cd3cf39..876e5fb 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1373,6 +1373,8 @@ static int br_ip6_multicast_query(struct net_bridge *br, br_multicast_query_received(br, port, &br->ip6_other_query, &saddr, max_delay); goto out; + } else if (!group) { + goto out; } mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group, vid);