bridge: multicast flood

Fix unsafe usage of RCU. Would never work on Alpha SMP because
of lack of rcu_dereference()

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 7a241c3..5b70fc0 100644 (file)
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -216,7 +216,7 @@ static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
 
        prev = NULL;
 
-       rp = br->router_list.first;
+       rp = rcu_dereference(br->router_list.first);
        p = mdst ? mdst->ports : NULL;
        while (p || rp) {
                lport = p ? p->port : NULL;
@@ -233,7 +233,7 @@ static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
                if ((unsigned long)lport >= (unsigned long)port)
                        p = p->next;
                if ((unsigned long)rport >= (unsigned long)port)
-                       rp = rp->next;
+                       rp = rcu_dereference(rp->next);
        }
 
        if (!prev)