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=-7.5 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 ADA41C43441 for ; Wed, 21 Nov 2018 19:06:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 745EB214F1 for ; Wed, 21 Nov 2018 19:06:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="YhKHQpEP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 745EB214F1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387535AbeKVFmQ (ORCPT ); Thu, 22 Nov 2018 00:42:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:36564 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730172AbeKVFmP (ORCPT ); Thu, 22 Nov 2018 00:42:15 -0500 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 577A2214D9; Wed, 21 Nov 2018 19:06:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542827202; bh=v8ACeI8bqYs+cqgcAzqGQI+vGd5wrdatGYKA9tw+Pfw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YhKHQpEP6TwM+hren4VqHuIe6A3OQNpw4mDXy8D9GR9TXRlofrUiD6hAHCrDEPyeg 4MYQwKzl02rtbQITm6JyKj908tvDHFnIu5wpg4Kjk82j2an3L3zICqR7j+LJR9hYmP Vp+7tMDoRsaF7KANQJ+p/wStKrokusHPPsz6+X0c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Li Shuang , Xin Long , David Ahern , "David S. Miller" Subject: [PATCH 4.19 04/42] ipv6: fix a dst leak when removing its exception Date: Wed, 21 Nov 2018 20:05:40 +0100 Message-Id: <20181121183148.133221399@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181121183147.869199006@linuxfoundation.org> References: <20181121183147.869199006@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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: Xin Long [ Upstream commit 761f60261b4401aa368d71d431b4c218af0efcee ] These is no need to hold dst before calling rt6_remove_exception_rt(). The call to dst_hold_safe() in ip6_link_failure() was for ip6_del_rt(), which has been removed in Commit 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes"). Otherwise, it will cause a dst leak. This patch is to simply remove the dst_hold_safe() call before calling rt6_remove_exception_rt() and also do the same in ip6_del_cached_rt(). It's safe, because the removal of the exception that holds its dst's refcnt is protected by rt6_exception_lock. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Fixes: 23fb93a4d3f1 ("net/ipv6: Cleanup exception and cache route handling") Reported-by: Li Shuang Signed-off-by: Xin Long Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/route.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2263,8 +2263,7 @@ static void ip6_link_failure(struct sk_b if (rt) { rcu_read_lock(); if (rt->rt6i_flags & RTF_CACHE) { - if (dst_hold_safe(&rt->dst)) - rt6_remove_exception_rt(rt); + rt6_remove_exception_rt(rt); } else { struct fib6_info *from; struct fib6_node *fn; @@ -3266,8 +3265,8 @@ static int ip6_del_cached_rt(struct rt6_ if (cfg->fc_flags & RTF_GATEWAY && !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway)) goto out; - if (dst_hold_safe(&rt->dst)) - rc = rt6_remove_exception_rt(rt); + + rc = rt6_remove_exception_rt(rt); out: return rc; }