From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: [PATCH 9/13 net-3.1-stable] route: fix ICMP redirect validation Date: Tue, 06 Dec 2011 16:33:39 -0500 (EST) Message-ID: <20111206.163339.676278798295465327.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:33979 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754487Ab1LFVdl (ORCPT ); Tue, 6 Dec 2011 16:33:41 -0500 Received: from localhost (nat-pool-rdu.redhat.com [66.187.233.202]) (authenticated bits=0) by shards.monkeyblade.net (8.14.4/8.14.4) with ESMTP id pB6LXd8Y024230 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NO) for ; Tue, 6 Dec 2011 13:33:40 -0800 Sender: netdev-owner@vger.kernel.org List-ID: From: Flavio Leitner [ Upstream commit 7cc9150ebe8ec06cafea9f1c10d92ddacf88d8ae ] The commit f39925dbde7788cfb96419c0f092b086aa325c0f (ipv4: Cache learned redirect information in inetpeer.) removed some ICMP packet validations which are required by RFC 1122, section 3.2.2.2: ... A Redirect message SHOULD be silently discarded if the new gateway address it specifies is not on the same connected (sub-) net through which the Redirect arrived [INTRO:2, Appendix A], or if the source of the Redirect is not the current first-hop gateway for the specified destination (see Section 3.3.1). Signed-off-by: Flavio Leitner Signed-off-by: David S. Miller --- net/ipv4/route.c | 36 +++++++++++++++++++++++++++++++----- 1 files changed, 31 insertions(+), 5 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index c3fcdb4..e9b273b 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1313,7 +1313,12 @@ static void rt_del(unsigned hash, struct rtable *rt) void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, __be32 saddr, struct net_device *dev) { + int s, i; struct in_device *in_dev = __in_dev_get_rcu(dev); + struct rtable *rt; + __be32 skeys[2] = { saddr, 0 }; + int ikeys[2] = { dev->ifindex, 0 }; + struct flowi4 fl4; struct inet_peer *peer; struct net *net; @@ -1336,13 +1341,34 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, goto reject_redirect; } - peer = inet_getpeer_v4(daddr, 1); - if (peer) { - peer->redirect_learned.a4 = new_gw; + memset(&fl4, 0, sizeof(fl4)); + fl4.daddr = daddr; + for (s = 0; s < 2; s++) { + for (i = 0; i < 2; i++) { + fl4.flowi4_oif = ikeys[i]; + fl4.saddr = skeys[s]; + rt = __ip_route_output_key(net, &fl4); + if (IS_ERR(rt)) + continue; - inet_putpeer(peer); + if (rt->dst.error || rt->dst.dev != dev || + rt->rt_gateway != old_gw) { + ip_rt_put(rt); + continue; + } + + if (!rt->peer) + rt_bind_peer(rt, rt->rt_dst, 1); + + peer = rt->peer; + if (peer) { + peer->redirect_learned.a4 = new_gw; + atomic_inc(&__rt_peer_genid); + } - atomic_inc(&__rt_peer_genid); + ip_rt_put(rt); + return; + } } return; -- 1.7.7.3