From 7865ece30f06072ea61f7db2ebbe24b632800e17 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Tue, 7 Jul 2015 15:55:56 +0200 Subject: [PATCH] bridge: mdb: zero out the local br_ip variable before use [ 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 Fixes: b0e9a30dd669 ("bridge: Add vlan id to multicast groups") Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/bridge/br_mdb.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c index 19942e38fd2d..ff61e200bf01 100644 --- a/net/bridge/br_mdb.c +++ b/net/bridge/br_mdb.c @@ -368,6 +368,7 @@ static int __br_mdb_add(struct net *net, struct net_bridge *br, 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_bridge *br, struct br_mdb_entry *entry) if (timer_pending(&br->multicast_querier_timer)) return -EBUSY; + memset(&ip, 0, sizeof(ip)); ip.proto = entry->addr.proto; if (ip.proto == htons(ETH_P_IP)) ip.u.ip4 = entry->addr.u.ip4; -- 2.34.1