4 files changed, 44 insertions, 3 deletions

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 2c45c069ea1..b524c36c127 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -538,6 +538,7 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 {
 	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 	struct net_bridge_fdb_entry *fdb;
+	bool fdb_modified = false;
 
 	/* some users want to always flood. */
 	if (hold_time(br) == 0)
@@ -558,10 +559,15 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 					source->dev->name);
 		} else {
 			/* fastpath: update of existing entry */
-			fdb->dst = source;
+			if (unlikely(source != fdb->dst)) {
+				fdb->dst = source;
+				fdb_modified = true;
+			}
 			fdb->updated = jiffies;
 			if (unlikely(added_by_user))
 				fdb->added_by_user = 1;
+			if (unlikely(fdb_modified))
+				fdb_notify(br, fdb, RTM_NEWNEIGH);
 		}
 	} else {
 		spin_lock(&br->hash_lock);
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 7985deaff52..04d6348fd53 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -147,8 +147,8 @@ static int br_handle_local_finish(struct sk_buff *skb)
 	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
 	u16 vid = 0;
 
-	br_vlan_get_tag(skb, &vid);
-	if (p->flags & BR_LEARNING)
+	/* check if vlan is allowed, to avoid spoofing */
+	if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid))
 		br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
 	return 0;	 /* process further */
 }
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 53d6e32965f..bc17210d4c5 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -589,6 +589,7 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
 			struct sk_buff *skb, u16 *vid);
 bool br_allowed_egress(struct net_bridge *br, const struct net_port_vlans *v,
 		       const struct sk_buff *skb);
+bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid);
 struct sk_buff *br_handle_vlan(struct net_bridge *br,
 			       const struct net_port_vlans *v,
 			       struct sk_buff *skb);
@@ -660,6 +661,12 @@ static inline bool br_allowed_egress(struct net_bridge *br,
 	return true;
 }
 
+static inline bool br_should_learn(struct net_bridge_port *p,
+				   struct sk_buff *skb, u16 *vid)
+{
+	return true;
+}
+
 static inline struct sk_buff *br_handle_vlan(struct net_bridge *br,
 					     const struct net_port_vlans *v,
 					     struct sk_buff *skb)
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 24c5cc55589..fcc95390f86 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -241,6 +241,34 @@ bool br_allowed_egress(struct net_bridge *br,
 	return false;
 }
 
+/* Called under RCU */
+bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
+{
+	struct net_bridge *br = p->br;
+	struct net_port_vlans *v;
+
+	if (!br->vlan_enabled)
+		return true;
+
+	v = rcu_dereference(p->vlan_info);
+	if (!v)
+		return false;
+
+	br_vlan_get_tag(skb, vid);
+	if (!*vid) {
+		*vid = br_get_pvid(v);
+		if (*vid == VLAN_N_VID)
+			return false;
+
+		return true;
+	}
+
+	if (test_bit(*vid, v->vlan_bitmap))
+		return true;
+
+	return false;
+}
+
 /* Must be protected by RTNL.
  * Must be called with vid in range from 1 to 4094 inclusive.
  */