]> git.proxmox.com Git - mirror_ubuntu-hirsute-kernel.git/commitdiff
bridge: fix smatch warning / potential null pointer dereference
authorLinus Lüssing <linus.luessing@web.de>
Wed, 11 Jun 2014 23:41:23 +0000 (01:41 +0200)
committerDavid S. Miller <davem@davemloft.net>
Thu, 12 Jun 2014 18:00:24 +0000 (11:00 -0700)
"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 dc4eb53a996a78bfb8ea07b47423ff5a3aadc362
("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>
net/bridge/br_multicast.c

index cd3cf394c4774483a9c1d1e3a6e60004c2b5b2ba..876e5fb2a786fa558d67854d724017de91c661f5 100644 (file)
@@ -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);