Merge tag 'batadv-net-for-davem-20160914' of git://git.open-mesh.org/linux-merge

Simon Wunderlich says:

====================
Here are two batman-adv bugfix patches:

 - Fix reference counting for last_bonding_candidate, by Sven Eckelmann

 - Fix head room reservation for ELP packets, by Linus Luessing
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/batman-adv/bat_v_elp.c

@@ -335,7 +335,7 @@ int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
 		goto out;
 
 	skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
-	elp_buff = skb_push(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN);
+	elp_buff = skb_put(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN);
 	elp_packet = (struct batadv_elp_packet *)elp_buff;
 	memset(elp_packet, 0, BATADV_ELP_HLEN);
 

net/batman-adv/routing.c

@@ -469,6 +469,29 @@ static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
 	return 0;
 }
 
+/**
+ * batadv_last_bonding_get - Get last_bonding_candidate of orig_node
+ * @orig_node: originator node whose last bonding candidate should be retrieved
+ *
+ * Return: last bonding candidate of router or NULL if not found
+ *
+ * The object is returned with refcounter increased by 1.
+ */
+static struct batadv_orig_ifinfo *
+batadv_last_bonding_get(struct batadv_orig_node *orig_node)
+{
+	struct batadv_orig_ifinfo *last_bonding_candidate;
+
+	spin_lock_bh(&orig_node->neigh_list_lock);
+	last_bonding_candidate = orig_node->last_bonding_candidate;
+
+	if (last_bonding_candidate)
+		kref_get(&last_bonding_candidate->refcount);
+	spin_unlock_bh(&orig_node->neigh_list_lock);
+
+	return last_bonding_candidate;
+}
+
 /**
  * batadv_last_bonding_replace - Replace last_bonding_candidate of orig_node
  * @orig_node: originator node whose bonding candidates should be replaced
@@ -539,7 +562,7 @@ batadv_find_router(struct batadv_priv *bat_priv,
 	 * router - obviously there are no other candidates.
 	 */
 	rcu_read_lock();
-	last_candidate = orig_node->last_bonding_candidate;
+	last_candidate = batadv_last_bonding_get(orig_node);
 	if (last_candidate)
 		last_cand_router = rcu_dereference(last_candidate->router);
 
@@ -631,6 +654,9 @@ batadv_find_router(struct batadv_priv *bat_priv,
 		batadv_orig_ifinfo_put(next_candidate);
 	}
 
+	if (last_candidate)
+		batadv_orig_ifinfo_put(last_candidate);
+
 	return router;
 }