Patch "ipv4: fix broadcast packets reception" has been added to the 4.4-stable tree

Patch "ipv4: fix broadcast packets reception" has been added to the 4.4-stable tree

[gregkh]

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

    ipv4: fix broadcast packets reception

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:
     ipv4-fix-broadcast-packets-reception.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 <stable@vger.kernel.org> know about it.


>From foo@baz Sat Apr 16 10:02:53 PDT 2016
From: Paolo Abeni <pabeni@redhat.com>
Date: Tue, 22 Mar 2016 09:19:38 +0100
Subject: ipv4: fix broadcast packets reception

From: Paolo Abeni <pabeni@redhat.com>

[ Upstream commit ad0ea1989cc4d5905941d0a9e62c63ad6d859cef ]

Currently, ingress ipv4 broadcast datagrams are dropped since,
in udp_v4_early_demux(), ip_check_mc_rcu() is invoked even on
bcast packets.

This patch addresses the issue, invoking ip_check_mc_rcu()
only for mcast packets.

Fixes: 6e5403093261 ("ipv4/udp: Verify multicast group is ours in upd_v4_early_demux()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/udp.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1990,10 +1990,14 @@ void udp_v4_early_demux(struct sk_buff *
 		if (!in_dev)
 			return;
 
-		ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
-				       iph->protocol);
-		if (!ours)
-			return;
+		/* we are supposed to accept bcast packets */
+		if (skb->pkt_type == PACKET_MULTICAST) {
+			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) {


Patches currently in stable-queue which might be from pabeni@redhat.com are

queue-4.4/ipv4-fix-broadcast-packets-reception.patch