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,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 98D05C43381 for ; Mon, 18 Mar 2019 09:42:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4732B2075C for ; Mon, 18 Mar 2019 09:42:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552902164; bh=yk7xUdqeH99YrZqC6L8/q5GhNvSRayH5+0aTZym/fCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AN3U9EjVwc9A3LfhKzbt0oyNLjIAJh6uSD355cTjgStHrEfv7DMDKshKBh6Q1GYKO cQz3b1VXDRQ92WhvfCylbQRJ3SE3qFzBIPv6LO29XUMWP3ZAlNVvxEopoF4atBJKzY mv5od4BHZw7NA+v/CQ4SGq44U2m94DeuffuUmNH4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727753AbfCRJmm (ORCPT ); Mon, 18 Mar 2019 05:42:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:40842 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728769AbfCRJcq (ORCPT ); Mon, 18 Mar 2019 05:32:46 -0400 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 CC198214AF; Mon, 18 Mar 2019 09:32:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552901565; bh=yk7xUdqeH99YrZqC6L8/q5GhNvSRayH5+0aTZym/fCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WIkShkTuJ9hF+DV/Rbwj1oo6typ9NI8lnJv6M6JuUk9F/0AX2ulGhglw5yM8mG6eg 4nr9y8CZsFNinGZPEn6JgAbfQTo8UW9QDvW24I+M/Bq6XNC3KkLtQrk/OIsHxiCPE2 eC/azIirQg1uQgu5KFPtUlAAKx7hihHyGwKWWJ5I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Abeni , David Ahern , "David S. Miller" Subject: [PATCH 4.19 31/52] ipv6: route: enforce RCU protection in rt6_update_exception_stamp_rt() Date: Mon, 18 Mar 2019 10:25:28 +0100 Message-Id: <20190318084017.211496750@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190318084013.532280682@linuxfoundation.org> References: <20190318084013.532280682@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni [ Upstream commit 193f3685d0546b0cea20c99894aadb70098e47bf ] We must access rt6_info->from under RCU read lock: move the dereference under such lock, with proper annotation. v1 -> v2: - avoid using multiple, racy, fetch operations for rt->from Fixes: a68886a69180 ("net/ipv6: Make from in rt6_info rcu protected") Signed-off-by: Paolo Abeni Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/route.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1623,15 +1623,15 @@ static int rt6_remove_exception_rt(struc static void rt6_update_exception_stamp_rt(struct rt6_info *rt) { struct rt6_exception_bucket *bucket; - struct fib6_info *from = rt->from; struct in6_addr *src_key = NULL; struct rt6_exception *rt6_ex; - - if (!from || - !(rt->rt6i_flags & RTF_CACHE)) - return; + struct fib6_info *from; rcu_read_lock(); + from = rcu_dereference(rt->from); + if (!from || !(rt->rt6i_flags & RTF_CACHE)) + goto unlock; + bucket = rcu_dereference(from->rt6i_exception_bucket); #ifdef CONFIG_IPV6_SUBTREES @@ -1650,6 +1650,7 @@ static void rt6_update_exception_stamp_r if (rt6_ex) rt6_ex->stamp = jiffies; +unlock: rcu_read_unlock(); }