IB/ipoib: Verify address handle validity on send

When the bonding device senses a carrier loss of its active slave it replaces
that slave with a new one. In between the times when the carrier of an IPoIB
device goes down and ipoib_neigh is destroyed, it is possible that the
bonding driver will send a packet on a new slave that uses an old ipoib_neigh.
This patch detects and prevents this from happenning.

Signed-off-by: Moni Shoua <monis at voltaire.com>
Signed-off-by: Or Gerlitz <ogerlitz at voltaire.com>
Acked-by: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -692,9 +692,10 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
 				goto out;
 			}
 		} else if (neigh->ah) {
-			if (unlikely(memcmp(&neigh->dgid.raw,
+			if (unlikely((memcmp(&neigh->dgid.raw,
 					    skb->dst->neighbour->ha + 4,
-					    sizeof(union ib_gid)))) {
+					    sizeof(union ib_gid))) ||
+					 (neigh->dev != dev))) {
 				spin_lock(&priv->lock);
 				/*
 				 * It's safe to call ipoib_put_ah() inside