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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 244C9C63793 for ; Mon, 19 Jul 2021 16:42:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B15961375 for ; Mon, 19 Jul 2021 16:42:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352225AbhGSQB1 (ORCPT ); Mon, 19 Jul 2021 12:01:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:59810 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345753AbhGSPE5 (ORCPT ); Mon, 19 Jul 2021 11:04:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 86A6760238; Mon, 19 Jul 2021 15:45:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626709530; bh=PPgBTkzggWDOjYGtn1EBckHWrI1Q6tPwwTuhJwolJ0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CWfonLFXz21n3Ufb1ZY5bfdZsmBBatUOIx6Y/vrNmot4BFgs+JSq4/3oqOiu+M9w2 rlCIA30FXxjrrSv7lwJn1cQxSCh5sJSayB4HMqCiHbpv0ZlY1uwuqNrlc1cd2rvKGq 81y8FMAISgjOm6CY4DTA8VUl89L3syF3+IfD8Kc8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikolay Aleksandrov , "David S. Miller" Subject: [PATCH 4.19 420/421] net: bridge: multicast: fix PIM hello router port marking race Date: Mon, 19 Jul 2021 16:53:51 +0200 Message-Id: <20210719145000.879567007@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nikolay Aleksandrov commit 04bef83a3358946bfc98a5ecebd1b0003d83d882 upstream. When a PIM hello packet is received on a bridge port with multicast snooping enabled, we mark it as a router port automatically, that includes adding that port the router port list. The multicast lock protects that list, but it is not acquired in the PIM message case leading to a race condition, we need to take it to fix the race. Cc: stable@vger.kernel.org Fixes: 91b02d3d133b ("bridge: mcast: add router port on PIM hello message") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/bridge/br_multicast.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1791,7 +1791,9 @@ static void br_multicast_pim(struct net_ pim_hdr_type(pimhdr) != PIM_TYPE_HELLO) return; + spin_lock(&br->multicast_lock); br_multicast_mark_router(br, port); + spin_unlock(&br->multicast_lock); } static int br_multicast_ipv4_rcv(struct net_bridge *br,