Merge tag 'batadv-net-for-davem-20160708' of git://git.open-mesh.org/linux-merge

Simon Wunderlich says:

====================
Here are a couple batman-adv bugfix patches, all by Sven Eckelmann:

 - Fix possible NULL pointer dereference for vlan_insert_tag (two patches)

 - Fix reference handling in some features, which may lead to reference
   leaks or invalid memory access (four patches)

 - Fix speedy join: DHCP packets handled by the gateway feature should
   be sent with 4-address unicast instead of 3-address unicast to make
   speedy join work. This fixes/speeds up DHCP assignment for clients
   which join a mesh for the first time. (one patch)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/batman-adv/bridge_loop_avoidance.c

@@ -177,10 +177,21 @@ static void batadv_backbone_gw_put(struct batadv_bla_backbone_gw *backbone_gw)
 static void batadv_claim_release(struct kref *ref)
 {
 	struct batadv_bla_claim *claim;
+	struct batadv_bla_backbone_gw *old_backbone_gw;
 
 	claim = container_of(ref, struct batadv_bla_claim, refcount);
 
-	batadv_backbone_gw_put(claim->backbone_gw);
+	spin_lock_bh(&claim->backbone_lock);
+	old_backbone_gw = claim->backbone_gw;
+	claim->backbone_gw = NULL;
+	spin_unlock_bh(&claim->backbone_lock);
+
+	spin_lock_bh(&old_backbone_gw->crc_lock);
+	old_backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
+	spin_unlock_bh(&old_backbone_gw->crc_lock);
+
+	batadv_backbone_gw_put(old_backbone_gw);
+
 	kfree_rcu(claim, rcu);
 }
 
@@ -418,9 +429,12 @@ static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac,
 		break;
 	}
 
-	if (vid & BATADV_VLAN_HAS_TAG)
+	if (vid & BATADV_VLAN_HAS_TAG) {
 		skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
 				      vid & VLAN_VID_MASK);
+		if (!skb)
+			goto out;
+	}
 
 	skb_reset_mac_header(skb);
 	skb->protocol = eth_type_trans(skb, soft_iface);
@@ -674,8 +688,10 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
 				 const u8 *mac, const unsigned short vid,
 				 struct batadv_bla_backbone_gw *backbone_gw)
 {
+	struct batadv_bla_backbone_gw *old_backbone_gw;
 	struct batadv_bla_claim *claim;
 	struct batadv_bla_claim search_claim;
+	bool remove_crc = false;
 	int hash_added;
 
 	ether_addr_copy(search_claim.addr, mac);
@@ -689,8 +705,10 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
 			return;
 
 		ether_addr_copy(claim->addr, mac);
+		spin_lock_init(&claim->backbone_lock);
 		claim->vid = vid;
 		claim->lasttime = jiffies;
+		kref_get(&backbone_gw->refcount);
 		claim->backbone_gw = backbone_gw;
 
 		kref_init(&claim->refcount);
@@ -718,15 +736,26 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
 			   "bla_add_claim(): changing ownership for %pM, vid %d\n",
 			   mac, BATADV_PRINT_VID(vid));
 
-		spin_lock_bh(&claim->backbone_gw->crc_lock);
-		claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
-		spin_unlock_bh(&claim->backbone_gw->crc_lock);
-		batadv_backbone_gw_put(claim->backbone_gw);
+		remove_crc = true;
 	}
-	/* set (new) backbone gw */
+
+	/* replace backbone_gw atomically and adjust reference counters */
+	spin_lock_bh(&claim->backbone_lock);
+	old_backbone_gw = claim->backbone_gw;
 	kref_get(&backbone_gw->refcount);
 	claim->backbone_gw = backbone_gw;
+	spin_unlock_bh(&claim->backbone_lock);
 
+	if (remove_crc) {
+		/* remove claim address from old backbone_gw */
+		spin_lock_bh(&old_backbone_gw->crc_lock);
+		old_backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
+		spin_unlock_bh(&old_backbone_gw->crc_lock);
+	}
+
+	batadv_backbone_gw_put(old_backbone_gw);
+
+	/* add claim address to new backbone_gw */
 	spin_lock_bh(&backbone_gw->crc_lock);
 	backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 	spin_unlock_bh(&backbone_gw->crc_lock);
@@ -736,6 +765,26 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
 	batadv_claim_put(claim);
 }
 
+/**
+ * batadv_bla_claim_get_backbone_gw - Get valid reference for backbone_gw of
+ *  claim
+ * @claim: claim whose backbone_gw should be returned
+ *
+ * Return: valid reference to claim::backbone_gw
+ */
+static struct batadv_bla_backbone_gw *
+batadv_bla_claim_get_backbone_gw(struct batadv_bla_claim *claim)
+{
+	struct batadv_bla_backbone_gw *backbone_gw;
+
+	spin_lock_bh(&claim->backbone_lock);
+	backbone_gw = claim->backbone_gw;
+	kref_get(&backbone_gw->refcount);
+	spin_unlock_bh(&claim->backbone_lock);
+
+	return backbone_gw;
+}
+
 /**
  * batadv_bla_del_claim - delete a claim from the claim hash
  * @bat_priv: the bat priv with all the soft interface information
@@ -760,10 +809,6 @@ static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
 			   batadv_choose_claim, claim);
 	batadv_claim_put(claim); /* reference from the hash is gone */
 
-	spin_lock_bh(&claim->backbone_gw->crc_lock);
-	claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
-	spin_unlock_bh(&claim->backbone_gw->crc_lock);
-
 	/* don't need the reference from hash_find() anymore */
 	batadv_claim_put(claim);
 }
@@ -1216,6 +1261,7 @@ static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
 				    struct batadv_hard_iface *primary_if,
 				    int now)
 {
+	struct batadv_bla_backbone_gw *backbone_gw;
 	struct batadv_bla_claim *claim;
 	struct hlist_head *head;
 	struct batadv_hashtable *hash;
@@ -1230,14 +1276,17 @@ static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
 
 		rcu_read_lock();
 		hlist_for_each_entry_rcu(claim, head, hash_entry) {
+			backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
 			if (now)
 				goto purge_now;
-			if (!batadv_compare_eth(claim->backbone_gw->orig,
+
+			if (!batadv_compare_eth(backbone_gw->orig,
 						primary_if->net_dev->dev_addr))
-				continue;
+				goto skip;
+
 			if (!batadv_has_timed_out(claim->lasttime,
 						  BATADV_BLA_CLAIM_TIMEOUT))
-				continue;
+				goto skip;
 
 			batadv_dbg(BATADV_DBG_BLA, bat_priv,
 				   "bla_purge_claims(): %pM, vid %d, time out\n",
@@ -1245,8 +1294,10 @@ static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
 
 purge_now:
 			batadv_handle_unclaim(bat_priv, primary_if,
-					      claim->backbone_gw->orig,
+					      backbone_gw->orig,
 					      claim->addr, claim->vid);
+skip:
+			batadv_backbone_gw_put(backbone_gw);
 		}
 		rcu_read_unlock();
 	}
@@ -1757,9 +1808,11 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb,
 bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
 		   unsigned short vid, bool is_bcast)
 {
+	struct batadv_bla_backbone_gw *backbone_gw;
 	struct ethhdr *ethhdr;
 	struct batadv_bla_claim search_claim, *claim = NULL;
 	struct batadv_hard_iface *primary_if;
+	bool own_claim;
 	bool ret;
 
 	ethhdr = eth_hdr(skb);
@@ -1794,8 +1847,12 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
 	}
 
 	/* if it is our own claim ... */
-	if (batadv_compare_eth(claim->backbone_gw->orig,
-			       primary_if->net_dev->dev_addr)) {
+	backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
+	own_claim = batadv_compare_eth(backbone_gw->orig,
+				       primary_if->net_dev->dev_addr);
+	batadv_backbone_gw_put(backbone_gw);
+
+	if (own_claim) {
 		/* ... allow it in any case */
 		claim->lasttime = jiffies;
 		goto allow;
@@ -1859,7 +1916,9 @@ bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
 {
 	struct ethhdr *ethhdr;
 	struct batadv_bla_claim search_claim, *claim = NULL;
+	struct batadv_bla_backbone_gw *backbone_gw;
 	struct batadv_hard_iface *primary_if;
+	bool client_roamed;
 	bool ret = false;
 
 	primary_if = batadv_primary_if_get_selected(bat_priv);
@@ -1889,8 +1948,12 @@ bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
 		goto allow;
 
 	/* check if we are responsible. */
-	if (batadv_compare_eth(claim->backbone_gw->orig,
-			       primary_if->net_dev->dev_addr)) {
+	backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
+	client_roamed = batadv_compare_eth(backbone_gw->orig,
+					   primary_if->net_dev->dev_addr);
+	batadv_backbone_gw_put(backbone_gw);
+
+	if (client_roamed) {
 		/* if yes, the client has roamed and we have
 		 * to unclaim it.
 		 */
@@ -1938,6 +2001,7 @@ int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset)
 	struct net_device *net_dev = (struct net_device *)seq->private;
 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
 	struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
+	struct batadv_bla_backbone_gw *backbone_gw;
 	struct batadv_bla_claim *claim;
 	struct batadv_hard_iface *primary_if;
 	struct hlist_head *head;
@@ -1962,17 +2026,21 @@ int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset)
 
 		rcu_read_lock();
 		hlist_for_each_entry_rcu(claim, head, hash_entry) {
-			is_own = batadv_compare_eth(claim->backbone_gw->orig,
+			backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
+
+			is_own = batadv_compare_eth(backbone_gw->orig,
 						    primary_addr);
 
-			spin_lock_bh(&claim->backbone_gw->crc_lock);
-			backbone_crc = claim->backbone_gw->crc;
-			spin_unlock_bh(&claim->backbone_gw->crc_lock);
+			spin_lock_bh(&backbone_gw->crc_lock);
+			backbone_crc = backbone_gw->crc;
+			spin_unlock_bh(&backbone_gw->crc_lock);
 			seq_printf(seq, " * %pM on %5d by %pM [%c] (%#.4x)\n",
 				   claim->addr, BATADV_PRINT_VID(claim->vid),
-				   claim->backbone_gw->orig,
+				   backbone_gw->orig,
 				   (is_own ? 'x' : ' '),
 				   backbone_crc);
+
+			batadv_backbone_gw_put(backbone_gw);
 		}
 		rcu_read_unlock();
 	}

net/batman-adv/distributed-arp-table.c

@@ -1009,9 +1009,12 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
 		if (!skb_new)
 			goto out;
 
-		if (vid & BATADV_VLAN_HAS_TAG)
+		if (vid & BATADV_VLAN_HAS_TAG) {
 			skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
 						  vid & VLAN_VID_MASK);
+			if (!skb_new)
+				goto out;
+		}
 
 		skb_reset_mac_header(skb_new);
 		skb_new->protocol = eth_type_trans(skb_new,
@@ -1089,9 +1092,12 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
 	 */
 	skb_reset_mac_header(skb_new);
 
-	if (vid & BATADV_VLAN_HAS_TAG)
+	if (vid & BATADV_VLAN_HAS_TAG) {
 		skb_new = vlan_insert_tag(skb_new, htons(ETH_P_8021Q),
 					  vid & VLAN_VID_MASK);
+		if (!skb_new)
+			goto out;
+	}
 
 	/* To preserve backwards compatibility, the node has choose the outgoing
 	 * format based on the incoming request packet type. The assumption is

net/batman-adv/originator.c

@@ -765,6 +765,8 @@ static void batadv_orig_node_release(struct kref *ref)
 	struct batadv_neigh_node *neigh_node;
 	struct batadv_orig_node *orig_node;
 	struct batadv_orig_ifinfo *orig_ifinfo;
+	struct batadv_orig_node_vlan *vlan;
+	struct batadv_orig_ifinfo *last_candidate;
 
 	orig_node = container_of(ref, struct batadv_orig_node, refcount);
 
@@ -782,8 +784,21 @@ static void batadv_orig_node_release(struct kref *ref)
 		hlist_del_rcu(&orig_ifinfo->list);
 		batadv_orig_ifinfo_put(orig_ifinfo);
 	}
+
+	last_candidate = orig_node->last_bonding_candidate;
+	orig_node->last_bonding_candidate = NULL;
 	spin_unlock_bh(&orig_node->neigh_list_lock);
 
+	if (last_candidate)
+		batadv_orig_ifinfo_put(last_candidate);
+
+	spin_lock_bh(&orig_node->vlan_list_lock);
+	hlist_for_each_entry_safe(vlan, node_tmp, &orig_node->vlan_list, list) {
+		hlist_del_rcu(&vlan->list);
+		batadv_orig_node_vlan_put(vlan);
+	}
+	spin_unlock_bh(&orig_node->vlan_list_lock);
+
 	/* Free nc_nodes */
 	batadv_nc_purge_orig(orig_node->bat_priv, orig_node, NULL);
 

net/batman-adv/routing.c

@@ -455,6 +455,29 @@ static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
 	return 0;
 }
 
+/**
+ * batadv_last_bonding_replace - Replace last_bonding_candidate of orig_node
+ * @orig_node: originator node whose bonding candidates should be replaced
+ * @new_candidate: new bonding candidate or NULL
+ */
+static void
+batadv_last_bonding_replace(struct batadv_orig_node *orig_node,
+			    struct batadv_orig_ifinfo *new_candidate)
+{
+	struct batadv_orig_ifinfo *old_candidate;
+
+	spin_lock_bh(&orig_node->neigh_list_lock);
+	old_candidate = orig_node->last_bonding_candidate;
+
+	if (new_candidate)
+		kref_get(&new_candidate->refcount);
+	orig_node->last_bonding_candidate = new_candidate;
+	spin_unlock_bh(&orig_node->neigh_list_lock);
+
+	if (old_candidate)
+		batadv_orig_ifinfo_put(old_candidate);
+}
+
 /**
  * batadv_find_router - find a suitable router for this originator
  * @bat_priv: the bat priv with all the soft interface information
@@ -562,10 +585,6 @@ batadv_find_router(struct batadv_priv *bat_priv,
 	}
 	rcu_read_unlock();
 
-	/* last_bonding_candidate is reset below, remove the old reference. */
-	if (orig_node->last_bonding_candidate)
-		batadv_orig_ifinfo_put(orig_node->last_bonding_candidate);
-
 	/* After finding candidates, handle the three cases:
 	 * 1) there is a next candidate, use that
 	 * 2) there is no next candidate, use the first of the list
@@ -574,21 +593,28 @@ batadv_find_router(struct batadv_priv *bat_priv,
 	if (next_candidate) {
 		batadv_neigh_node_put(router);
 
-		/* remove references to first candidate, we don't need it. */
-		if (first_candidate) {
-			batadv_neigh_node_put(first_candidate_router);
-			batadv_orig_ifinfo_put(first_candidate);
-		}
+		kref_get(&next_candidate_router->refcount);
 		router = next_candidate_router;
-		orig_node->last_bonding_candidate = next_candidate;
+		batadv_last_bonding_replace(orig_node, next_candidate);
 	} else if (first_candidate) {
 		batadv_neigh_node_put(router);
 
-		/* refcounting has already been done in the loop above. */
+		kref_get(&first_candidate_router->refcount);
 		router = first_candidate_router;
-		orig_node->last_bonding_candidate = first_candidate;
+		batadv_last_bonding_replace(orig_node, first_candidate);
 	} else {
-		orig_node->last_bonding_candidate = NULL;
+		batadv_last_bonding_replace(orig_node, NULL);
+	}
+
+	/* cleanup of candidates */
+	if (first_candidate) {
+		batadv_neigh_node_put(first_candidate_router);
+		batadv_orig_ifinfo_put(first_candidate);
+	}
+
+	if (next_candidate) {
+		batadv_neigh_node_put(next_candidate_router);
+		batadv_orig_ifinfo_put(next_candidate);
 	}
 
 	return router;

net/batman-adv/send.c

@@ -424,8 +424,8 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 	struct batadv_orig_node *orig_node;
 
 	orig_node = batadv_gw_get_selected_orig(bat_priv);
-	return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
-				       orig_node, vid);
+	return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
+				       BATADV_P_DATA, orig_node, vid);
 }
 
 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)

net/batman-adv/types.h

@@ -330,7 +330,9 @@ struct batadv_orig_node {
 	DECLARE_BITMAP(bcast_bits, BATADV_TQ_LOCAL_WINDOW_SIZE);
 	u32 last_bcast_seqno;
 	struct hlist_head neigh_list;
-	/* neigh_list_lock protects: neigh_list and router */
+	/* neigh_list_lock protects: neigh_list, ifinfo_list,
+	 * last_bonding_candidate and router
+	 */
 	spinlock_t neigh_list_lock;
 	struct hlist_node hash_entry;
 	struct batadv_priv *bat_priv;
@@ -1042,6 +1044,7 @@ struct batadv_bla_backbone_gw {
  * @addr: mac address of claimed non-mesh client
  * @vid: vlan id this client was detected on
  * @backbone_gw: pointer to backbone gw claiming this client
+ * @backbone_lock: lock protecting backbone_gw pointer
  * @lasttime: last time we heard of claim (locals only)
  * @hash_entry: hlist node for batadv_priv_bla::claim_hash
  * @refcount: number of contexts the object is used
@@ -1051,6 +1054,7 @@ struct batadv_bla_claim {
 	u8 addr[ETH_ALEN];
 	unsigned short vid;
 	struct batadv_bla_backbone_gw *backbone_gw;
+	spinlock_t backbone_lock; /* protects backbone_gw */
 	unsigned long lasttime;
 	struct hlist_node hash_entry;
 	struct rcu_head rcu;