bridge: Fix possibly wrong MLD queries' ethernet source address

The ipv6_dev_get_saddr() is currently called with an uninitialized destination address. Although in tests it usually seemed to nevertheless always fetch the right source address, there seems to be a possible race condition. Therefore this commit changes this, first setting the destination address and only after that fetching the source address. Reported-by: Jan Beulich <[email protected]> Signed-off-by: Linus Lüssing <[email protected]> Signed-off-by: David S. Miller <[email protected]>
redpig · Mar 23, 2011 · a7bff75 · a7bff75
1 parent 6a1fef6
commit a7bff75
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
@@ -445,9 +445,9 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
 	ip6h->payload_len = htons(8 + sizeof(*mldq));
 	ip6h->nexthdr = IPPROTO_HOPOPTS;
 	ip6h->hop_limit = 1;
+	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
 	ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
 			   &ip6h->saddr);
-	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
 	ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
 
 	hopopt = (u8 *)(ip6h + 1);