From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752751AbbFQWcf (ORCPT ); Wed, 17 Jun 2015 18:32:35 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:36071 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752379AbbFQWbJ (ORCPT ); Wed, 17 Jun 2015 18:31:09 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Shawn Bohrer , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 122/122] ipv4/udp: Verify multicast group is ours in upd_v4_early_demux() Date: Wed, 17 Jun 2015 15:29:09 -0700 Message-Id: <1434580149-3095-123-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1434580149-3095-1-git-send-email-kamal@canonical.com> References: <1434580149-3095-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11-ckt22 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Shawn Bohrer [ Upstream commit 6e540309326188f769e03bb4c6dd8ff6752930c2 ] 421b3885bf6d56391297844f43fb7154a6396e12 "udp: ipv4: Add udp early demux" introduced a regression that allowed sockets bound to INADDR_ANY to receive packets from multicast groups that the socket had not joined. For example a socket that had joined 224.168.2.9 could also receive packets from 225.168.2.9 despite not having joined that group if ip_early_demux is enabled. Fix this by calling ip_check_mc_rcu() in udp_v4_early_demux() to verify that the multicast packet is indeed ours. Signed-off-by: Shawn Bohrer Reported-by: Yurij M. Plotnikov Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- net/ipv4/udp.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 7841ffd..b1adb69 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -90,6 +90,7 @@ #include #include #include +#include #include #include #include @@ -1922,6 +1923,7 @@ void udp_v4_early_demux(struct sk_buff *skb) struct sock *sk; struct dst_entry *dst; int dif = skb->dev->ifindex; + int ours; /* validate the packet */ if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) @@ -1931,14 +1933,24 @@ void udp_v4_early_demux(struct sk_buff *skb) uh = udp_hdr(skb); if (skb->pkt_type == PACKET_BROADCAST || - skb->pkt_type == PACKET_MULTICAST) + skb->pkt_type == PACKET_MULTICAST) { + struct in_device *in_dev = __in_dev_get_rcu(skb->dev); + + if (!in_dev) + return; + + ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, + iph->protocol); + if (!ours) + return; sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, uh->source, iph->saddr, dif); - else if (skb->pkt_type == PACKET_HOST) + } else if (skb->pkt_type == PACKET_HOST) { sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, uh->source, iph->saddr, dif); - else + } else { return; + } if (!sk) return; -- 1.9.1