Patch "ipv6: icmp6: Allow icmp messages to be looped back" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

ipv6: icmp6: Allow icmp messages to be looped back

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ipv6-icmp6-allow-icmp-messages-to-be-looped-back.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Brendan McGrath <[email protected]>
Date: Wed, 13 Dec 2017 22:14:57 +1100
Subject: ipv6: icmp6: Allow icmp messages to be looped back

From: Brendan McGrath <[email protected]>

[ Upstream commit 588753f1eb18978512b1c9b85fddb457d46f9033 ]

One example of when an ICMPv6 packet is required to be looped back is when a host acts as both a Multicast Listener and a Multicast Router.

A Multicast Router will listen on address ff02::16 for MLDv2 messages.

Currently, MLDv2 messages originating from a Multicast Listener running on the same host as the Multicast Router are not being delivered to the Multicast Router. This is due to dst.input being assigned the default value of dst_discard.

This results in the packet being looped back but discarded before being delivered to the Multicast Router.

This patch sets dst.input to ip6_input to ensure a looped back packet is delivered to the Multicast Router.

---
 net/ipv6/route.c |    1 +
 1 file changed, 1 insertion(+)

@@ -1614,6 +1614,7 @@ struct dst_entry *icmp6_dst_alloc(struct
 	}
 
 	rt->dst.flags |= DST_HOST;
+	rt->dst.input = ip6_input;
 	rt->dst.output  = ip6_output;
 	atomic_set(&rt->dst.__refcnt, 1);
 	rt->rt6i_gateway  = fl6->daddr;

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/ipv6-icmp6-allow-icmp-messages-to-be-looped-back.patch