ipv6: don't let node/interface scoped multicast traffic escape on the wire

Reported-by: Erik Hugne <erik.hugne@ericsson.com>
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>

1 files changed, 7 insertions, 0 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index c953825f9098..155eccfa7760 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -120,6 +120,13 @@ static int ip6_finish_output2(struct sk_buff *skb)
 
                 IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
                                 skb->len);
+
+                if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
+                    IPV6_ADDR_SCOPE_NODELOCAL &&
+                    !(dev->flags & IFF_LOOPBACK)) {
+                        kfree_skb(skb);
+                        return 0;
+                }
         }
 
         rcu_read_lock_bh();