[BRIDGE]: Packets leaking out of disabled/blocked ports.

This patch fixes some packet leakage in bridge.  The bridging code was
allowing forward table entries to be generated even if a device was
being blocked. The fix is to not add forwarding database entries
unless the port is active.

The bug arose as part of the conversion to processing STP frames
through normal receive path (in 2.6.17).

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Acked-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 2 deletions

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 69b70977f00..eb57502bb26 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -384,6 +384,11 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
         if (hold_time(br) == 0)
                 return;
 
+        /* ignore packets unless we are using this port */
+        if (!(source->state == BR_STATE_LEARNING ||
+              source->state == BR_STATE_FORWARDING))
+                return;
+
         fdb = fdb_find(head, addr);
         if (likely(fdb)) {
                 /* attempt to update an entry for a local interface */
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 5c18595b761..6f468fc3357 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -101,9 +101,8 @@ static int br_handle_local_finish(struct sk_buff *skb)
 {
         struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
 
-        if (p && p->state != BR_STATE_DISABLED)
+        if (p)
                 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
-
         return 0;        /* process further */
 }