From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Sun, 10 Feb 2013 05:35:22 +0000 (+0000)
Subject: ipv6: don't accept multicast traffic with scope 0
X-Git-Tag: v3.8.6~10
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=be0013681e301ab076b472f46de5afb1407b756c;p=karo-tx-linux.git

ipv6: don't accept multicast traffic with scope 0

[ Upstream commit 20314092c1b41894d8c181bf9aa6f022be2416aa ]

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

Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Cc: Erik Hugne <erik.hugne@ericsson.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index b19685219916..db70b8819a21 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -118,6 +118,15 @@ 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