[ 3.5.y.z extended stable ] Patch "ipv6: don't accept multicast traffic with scope 0" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ipv6: don't accept multicast traffic with scope 0

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From f8c161ee7246233ddfb110499d3174d8f093a425 Mon Sep 17 00:00:00 2001
From: Hannes Frederic Sowa <hannes at stressinduktion.org>
Date: Sun, 10 Feb 2013 05:35:22 +0000
Subject: [PATCH] ipv6: don't accept multicast traffic with scope 0

commit 20314092c1b41894d8c181bf9aa6f022be2416aa upstream.

v2:
a) moved before multicast source address check
b) changed comment to netdev style

Cc: Erik Hugne <erik.hugne at ericsson.com>
Cc: YOSHIFUJI Hideaki <yoshfuji at linux-ipv6.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji at linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji at linux-ipv6.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv6/ip6_input.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 61dfb1d..311eac7 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -111,6 +111,15 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt
 	    ipv6_addr_loopback(&hdr->daddr))
 		goto err;

+	/* RFC4291 2.7
+	 * Nodes must not originate a packet to a multicast address whose scope
+	 * field contains the reserved value 0; if such a packet is received, it
+	 * must be silently dropped.
+	 */
+	if (ipv6_addr_is_multicast(&hdr->daddr) &&
+	    IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
+		goto err;
+
 	/*
 	 * RFC4291 2.7
 	 * Multicast addresses must not be used as source addresses in IPv6
--
1.8.1.2