bridge: don't try to update timers in case of broken MLD queries

[ Upstream commit 248ba8ec05a2c3b118c2224e57eb10c128176ab1 ]

Currently we are reading an uninitialized value for the max_delay
variable when snooping an MLD query message of invalid length and would
update our timers with that.

Fixing this by simply ignoring such broken MLD queries (just like we do
for IGMP already).

This is a regression introduced by:
"bridge: disable snooping if there is no querier" (b00589af3b04)

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index d6448e35e02712682953d3d617aeac3b5f40737e..75a81281c97937a48cf88b7a350d437b7c4b5574 100644 (file)
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1185,7 +1185,7 @@ static int br_ip6_multicast_query(struct net_bridge *br,
                max_delay = msecs_to_jiffies(ntohs(mld->mld_maxdelay));
                if (max_delay)
                        group = &mld->mld_mca;
-       } else if (skb->len >= sizeof(*mld2q)) {
+       } else {
                if (!pskb_may_pull(skb, sizeof(*mld2q))) {
                        err = -EINVAL;
                        goto out;