Merge branch 'tipc-topology-server-fixes'

Parthasarathy Bhuvaragan says:

====================
tipc: topology server fixes

The following commits fixes two race conditions causing general
protection faults.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/subscr.c

@@ -52,7 +52,6 @@ struct tipc_subscriber {
 	struct list_head subscrp_list;
 };
 
-static void tipc_subscrp_delete(struct tipc_subscription *sub);
 static void tipc_subscrb_put(struct tipc_subscriber *subscriber);
 
 /**
@@ -197,15 +196,19 @@ static void tipc_subscrb_subscrp_delete(struct tipc_subscriber *subscriber,
 {
 	struct list_head *subscription_list = &subscriber->subscrp_list;
 	struct tipc_subscription *sub, *temp;
+	u32 timeout;
 
 	spin_lock_bh(&subscriber->lock);
 	list_for_each_entry_safe(sub, temp, subscription_list,  subscrp_list) {
 		if (s && memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr)))
 			continue;
 
-		tipc_nametbl_unsubscribe(sub);
-		list_del(&sub->subscrp_list);
-		tipc_subscrp_delete(sub);
+		timeout = htohl(sub->evt.s.timeout, sub->swap);
+		if (timeout == TIPC_WAIT_FOREVER || del_timer(&sub->timer)) {
+			tipc_nametbl_unsubscribe(sub);
+			list_del(&sub->subscrp_list);
+			tipc_subscrp_put(sub);
+		}
 
 		if (s)
 			break;
@@ -236,18 +239,12 @@ static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
 	tipc_subscrb_put(subscriber);
 }
 
-static void tipc_subscrp_delete(struct tipc_subscription *sub)
-{
-	u32 timeout = htohl(sub->evt.s.timeout, sub->swap);
-
-	if (timeout == TIPC_WAIT_FOREVER || del_timer(&sub->timer))
-		tipc_subscrp_put(sub);
-}
-
 static void tipc_subscrp_cancel(struct tipc_subscr *s,
 				struct tipc_subscriber *subscriber)
 {
+	tipc_subscrb_get(subscriber);
 	tipc_subscrb_subscrp_delete(subscriber, s);
+	tipc_subscrb_put(subscriber);
 }
 
 static struct tipc_subscription *tipc_subscrp_create(struct net *net,