Patch "bridge: mdb: zero out the local br_ip variable before use" has been added to the 4.1-stable tree

[<gregkh@linuxfoundation.org>]

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

    bridge: mdb: zero out the local br_ip variable before use

to the 4.1-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:
     bridge-mdb-zero-out-the-local-br_ip-variable-before-use.patch
and it can be found in the queue-4.1 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 Sep 26 11:13:07 PDT 2015
From: Nikolay Aleksandrov <razor@blackwall.org>
Date: Tue, 7 Jul 2015 15:55:56 +0200
Subject: bridge: mdb: zero out the local br_ip variable before use

From: Nikolay Aleksandrov <razor@blackwall.org>

[ Upstream commit f1158b74e54f2e2462ba5e2f45a118246d9d5b43 ]

Since commit b0e9a30dd669 ("bridge: Add vlan id to multicast groups")
there's a check in br_ip_equal() for a matching vlan id, but the mdb
functions were not modified to use (or at least zero it) so when an
entry was added it would have a garbage vlan id (from the local br_ip
variable in __br_mdb_add/del) and this would prevent it from being
matched and also deleted. So zero out the whole local ip var to protect
ourselves from future changes and also to fix the current bug, since
there's no vlan id support in the mdb uapi - use always vlan id 0.
Example before patch:
root@debian:~# bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb
dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb del dev br0 port eth1 grp 239.0.0.1 permanent
RTNETLINK answers: Invalid argument

After patch:
root@debian:~# bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb
dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb del dev br0 port eth1 grp 239.0.0.1 permanent
root@debian:~# bridge mdb

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Fixes: b0e9a30dd669 ("bridge: Add vlan id to multicast groups")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/bridge/br_mdb.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -371,6 +371,7 @@ static int __br_mdb_add(struct net *net,
 	if (!p || p->br != br || p->state == BR_STATE_DISABLED)
 		return -EINVAL;
 
+	memset(&ip, 0, sizeof(ip));
 	ip.proto = entry->addr.proto;
 	if (ip.proto == htons(ETH_P_IP))
 		ip.u.ip4 = entry->addr.u.ip4;
@@ -417,6 +418,7 @@ static int __br_mdb_del(struct net_bridg
 	if (!netif_running(br->dev) || br->multicast_disabled)
 		return -EINVAL;
 
+	memset(&ip, 0, sizeof(ip));
 	ip.proto = entry->addr.proto;
 	if (ip.proto == htons(ETH_P_IP)) {
 		if (timer_pending(&br->ip4_other_query.timer))


Patches currently in stable-queue which might be from razor@blackwall.org are

queue-4.1/bridge-mdb-zero-out-the-local-br_ip-variable-before-use.patch