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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 D2B7AC10F11 for ; Wed, 24 Apr 2019 18:09:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B46820652 for ; Wed, 24 Apr 2019 18:09:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556129398; bh=13z6LkR89jNKfJimZNxW0tKPd4BDNDUOV/SQJnh1vG0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FGCiWgRmQ88MIdkzeQZN11uvRD1Rv/pH3sW8gvKBtu9tGRH5E2nnylA3GTkCN1Iai kKsrGKtscAZPOwz9a9R+dl1yaFJKaJ6jNyBVuNXh0pJ/pKoC1rJCxVIMtFOYEgDWPG Zf7OpYoSDMNOlg2TgCSz49D1lmAVMh/9DCk4CG5E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387828AbfDXSJ5 (ORCPT ); Wed, 24 Apr 2019 14:09:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:39036 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388108AbfDXROt (ORCPT ); Wed, 24 Apr 2019 13:14:49 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 76EA0206BA; Wed, 24 Apr 2019 17:14:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126089; bh=13z6LkR89jNKfJimZNxW0tKPd4BDNDUOV/SQJnh1vG0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=llIUT/34r2YMMtnGTURrizTlu24OTzWdojXZMwSjW9SOc8p3pty2SZqE7ZtgC6AmU nVzCBlQV4y1MmCpHDaZh3wVfxLr7TsKdaV+6FoihnyZC1B1lVzW3/OJXLv9TUrMtgd MRqfWrWmac3V1+JlU1uGTjPblHdncdh2e/YxkJ3I= 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 3.18 091/104] net: bridge: multicast: use rcu to access port list from br_multicast_start_querier Date: Wed, 24 Apr 2019 19:09:48 +0200 Message-Id: <20190424170909.238142357@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170839.996641496@linuxfoundation.org> References: <20190424170839.996641496@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nikolay Aleksandrov [ Upstream commit c5b493ce192bd7a4e7bd073b5685aad121eeef82 ] br_multicast_start_querier() walks over the port list but it can be called from a timer with only multicast_lock held which doesn't protect the port list, so use RCU to walk over it. Fixes: c83b8fab06fc ("bridge: Restart queries when last querier expires") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/bridge/br_multicast.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -2023,7 +2023,8 @@ static void br_multicast_start_querier(s __br_multicast_open(br, query); - list_for_each_entry(port, &br->port_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(port, &br->port_list, list) { if (port->state == BR_STATE_DISABLED || port->state == BR_STATE_BLOCKING) continue; @@ -2035,6 +2036,7 @@ static void br_multicast_start_querier(s br_multicast_enable(&port->ip6_own_query); #endif } + rcu_read_unlock(); } int br_multicast_toggle(struct net_bridge *br, unsigned long val)