Commit 6c03ee8b authored Jun 12, 2014 by Linus Lüssing Committed by David S. Miller Jun 12, 2014

bridge: fix smatch warning / potential null pointer dereference



"New smatch warnings:
  net/bridge/br_multicast.c:1368 br_ip6_multicast_query() error:
    we previously assumed 'group' could be null (see line 1349)"

In the rare (sort of broken) case of a query having a Maximum
Response Delay of zero, we could create a potential null pointer
dereference.

Fixing this by skipping the multicast specific MLD Query parsing again
if no multicast group address is available.

Introduced by dc4eb53a
("bridge: adhere to querier election mechanism specified by RFCs")

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 17958438

net/bridge/br_multicast.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1373,6 +1373,8 @@ static int br_ip6_multicast_query(struct net_bridge *br,
		br_multicast_query_received(br, port, &br->ip6_other_query,
		&saddr, max_delay);
		goto out;
		} else if (!group) {
		goto out;
		}

		mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group, vid);