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 d6448e3..75a8128 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;