path: root/net
diff options
authorLinus Lüssing <linus.luessing@web.de>2014-03-10 22:25:25 +0100
committerDavid S. Miller <davem@davemloft.net>2014-03-11 23:22:10 -0400
commit20a599bec95a52fa72432b2376a2ce47c5bb68fb (patch)
tree37e01659d8e8974706ecc4042fff98bba274a59a /net
parent9ed973cc40c588abeaa58aea0683ea665132d11d (diff)
bridge: multicast: enable snooping on general queries only
Without this check someone could easily create a denial of service by injecting multicast-specific queries to enable the bridge snooping part if no real querier issuing periodic general queries is present on the link which would result in the bridge wrongly shutting down ports for multicast traffic as the bridge did not learn about these listeners. With this patch the snooping code is enabled upon receiving valid, general queries only. Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 5 insertions, 3 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index e56bae4f59c..93067ecdb9a 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1127,9 +1127,10 @@ static void br_multicast_query_received(struct net_bridge *br,
struct net_bridge_port *port,
struct bridge_mcast_querier *querier,
int saddr,
+ bool is_general_query,
unsigned long max_delay)
- if (saddr)
+ if (saddr && is_general_query)
br_multicast_update_querier_timer(br, querier, max_delay);
else if (timer_pending(&querier->timer))
@@ -1190,7 +1191,7 @@ static int br_ip4_multicast_query(struct net_bridge *br,
br_multicast_query_received(br, port, &br->ip4_querier, !!iph->saddr,
- max_delay);
+ !group, max_delay);
if (!group)
goto out;
@@ -1282,7 +1283,8 @@ static int br_ip6_multicast_query(struct net_bridge *br,
br_multicast_query_received(br, port, &br->ip6_querier,
- !ipv6_addr_any(&ip6h->saddr), max_delay);
+ !ipv6_addr_any(&ip6h->saddr),
+ is_general_query, max_delay);
if (!group)
goto out;