1 files changed, 34 insertions, 13 deletions

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index eae898c3cff7..257ac4e25f6d 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -179,7 +179,8 @@ struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
 		break;
 #endif
 	default:
-		return NULL;
+		ip.proto = 0;
+		ether_addr_copy(ip.dst.mac_addr, eth_hdr(skb)->h_dest);
 	}
 
 	return br_mdb_ip_get_rcu(br, &ip);
@@ -1203,6 +1204,10 @@ void br_multicast_host_join(struct net_bridge_mdb_entry *mp, bool notify)
 		if (notify)
 			br_mdb_notify(mp->br->dev, mp, NULL, RTM_NEWMDB);
 	}
+
+	if (br_group_is_l2(&mp->addr))
+		return;
+
 	mod_timer(&mp->timer, jiffies + mp->br->multicast_membership_interval);
 }
 
@@ -1254,8 +1259,8 @@ __br_multicast_add_group(struct net_bridge *br,
 			break;
 	}
 
-	p = br_multicast_new_port_group(port, group, *pp, 0, src, filter_mode,
-					RTPROT_KERNEL);
+	p = br_multicast_new_port_group(port, group, *pp, 0, src,
+					filter_mode, RTPROT_KERNEL);
 	if (unlikely(!p)) {
 		p = ERR_PTR(-ENOMEM);
 		goto out;
@@ -3286,7 +3291,7 @@ static inline void br_ip6_multicast_join_snoopers(struct net_bridge *br)
 }
 #endif
 
-static void br_multicast_join_snoopers(struct net_bridge *br)
+void br_multicast_join_snoopers(struct net_bridge *br)
 {
 	br_ip4_multicast_join_snoopers(br);
 	br_ip6_multicast_join_snoopers(br);
@@ -3317,7 +3322,7 @@ static inline void br_ip6_multicast_leave_snoopers(struct net_bridge *br)
 }
 #endif
 
-static void br_multicast_leave_snoopers(struct net_bridge *br)
+void br_multicast_leave_snoopers(struct net_bridge *br)
 {
 	br_ip4_multicast_leave_snoopers(br);
 	br_ip6_multicast_leave_snoopers(br);
@@ -3336,9 +3341,6 @@ static void __br_multicast_open(struct net_bridge *br,
 
 void br_multicast_open(struct net_bridge *br)
 {
-	if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
-		br_multicast_join_snoopers(br);
-
 	__br_multicast_open(br, &br->ip4_own_query);
 #if IS_ENABLED(CONFIG_IPV6)
 	__br_multicast_open(br, &br->ip6_own_query);
@@ -3354,9 +3356,6 @@ void br_multicast_stop(struct net_bridge *br)
 	del_timer_sync(&br->ip6_other_query.timer);
 	del_timer_sync(&br->ip6_own_query.timer);
 #endif
-
-	if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
-		br_multicast_leave_snoopers(br);
 }
 
 void br_multicast_dev_del(struct net_bridge *br)
@@ -3487,6 +3486,7 @@ static void br_multicast_start_querier(struct net_bridge *br,
 int br_multicast_toggle(struct net_bridge *br, unsigned long val)
 {
 	struct net_bridge_port *port;
+	bool change_snoopers = false;
 
 	spin_lock_bh(&br->multicast_lock);
 	if (!!br_opt_get(br, BROPT_MULTICAST_ENABLED) == !!val)
@@ -3495,7 +3495,7 @@ int br_multicast_toggle(struct net_bridge *br, unsigned long val)
 	br_mc_disabled_update(br->dev, val);
 	br_opt_toggle(br, BROPT_MULTICAST_ENABLED, !!val);
 	if (!br_opt_get(br, BROPT_MULTICAST_ENABLED)) {
-		br_multicast_leave_snoopers(br);
+		change_snoopers = true;
 		goto unlock;
 	}
 
@@ -3506,9 +3506,30 @@ int br_multicast_toggle(struct net_bridge *br, unsigned long val)
 	list_for_each_entry(port, &br->port_list, list)
 		__br_multicast_enable_port(port);
 
+	change_snoopers = true;
+
 unlock:
 	spin_unlock_bh(&br->multicast_lock);
 
+	/* br_multicast_join_snoopers has the potential to cause
+	 * an MLD Report/Leave to be delivered to br_multicast_rcv,
+	 * which would in turn call br_multicast_add_group, which would
+	 * attempt to acquire multicast_lock. This function should be
+	 * called after the lock has been released to avoid deadlocks on
+	 * multicast_lock.
+	 *
+	 * br_multicast_leave_snoopers does not have the problem since
+	 * br_multicast_rcv first checks BROPT_MULTICAST_ENABLED, and
+	 * returns without calling br_multicast_ipv4/6_rcv if it's not
+	 * enabled. Moved both functions out just for symmetry.
+	 */
+	if (change_snoopers) {
+		if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
+			br_multicast_join_snoopers(br);
+		else
+			br_multicast_leave_snoopers(br);
+	}
+
 	return 0;
 }
 
@@ -3690,7 +3711,7 @@ bool br_multicast_has_querier_anywhere(struct net_device *dev, int proto)
 	memset(&eth, 0, sizeof(eth));
 	eth.h_proto = htons(proto);
 
-	ret = br_multicast_querier_exists(br, &eth);
+	ret = br_multicast_querier_exists(br, &eth, NULL);
 
 unlock:
 	rcu_read_unlock();