5 files changed, 22 insertions, 8 deletions

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 870bdf2e082c..dea09096ad0f 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -25,7 +25,7 @@ static inline int should_deliver(const struct net_bridge_port *p,
 
 	vg = nbp_vlan_group_rcu(p);
 	return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
-		(br_mst_is_enabled(p->br) || p->state == BR_STATE_FORWARDING) &&
+		(br_mst_is_enabled(p) || p->state == BR_STATE_FORWARDING) &&
 		br_allowed_egress(vg, skb) && nbp_switchdev_allowed_egress(p, skb) &&
 		!br_skb_isolated(p, skb);
 }
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 98c5b9c3145f..ca3a637d7cca 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -386,6 +386,7 @@ void br_dev_delete(struct net_device *dev, struct list_head *head)
 		del_nbp(p);
 	}
 
+	br_mst_uninit(br);
 	br_recalculate_neigh_suppress_enabled(br);
 
 	br_fdb_delete_by_port(br, NULL, 0, 1);
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 67b4c905e49a..777fa869c1a1 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -94,7 +94,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
 
 	br = p->br;
 
-	if (br_mst_is_enabled(br)) {
+	if (br_mst_is_enabled(p)) {
 		state = BR_STATE_FORWARDING;
 	} else {
 		if (p->state == BR_STATE_DISABLED) {
@@ -429,7 +429,7 @@ static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
 		return RX_HANDLER_PASS;
 
 forward:
-	if (br_mst_is_enabled(p->br))
+	if (br_mst_is_enabled(p))
 		goto defer_stp_filtering;
 
 	switch (p->state) {
diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
index 3f24b4ee49c2..43a300ae6bfa 100644
--- a/net/bridge/br_mst.c
+++ b/net/bridge/br_mst.c
@@ -22,6 +22,12 @@ bool br_mst_enabled(const struct net_device *dev)
 }
 EXPORT_SYMBOL_GPL(br_mst_enabled);
 
+void br_mst_uninit(struct net_bridge *br)
+{
+	if (br_opt_get(br, BROPT_MST_ENABLED))
+		static_branch_dec(&br_mst_used);
+}
+
 int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids)
 {
 	const struct net_bridge_vlan_group *vg;
@@ -225,9 +231,9 @@ int br_mst_set_enabled(struct net_bridge *br, bool on,
 		return err;
 
 	if (on)
-		static_branch_enable(&br_mst_used);
+		static_branch_inc(&br_mst_used);
 	else
-		static_branch_disable(&br_mst_used);
+		static_branch_dec(&br_mst_used);
 
 	br_opt_toggle(br, BROPT_MST_ENABLED, on);
 	return 0;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 16be5d250402..7280c4e9305f 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1935,10 +1935,12 @@ static inline bool br_vlan_state_allowed(u8 state, bool learn_allow)
 /* br_mst.c */
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
 DECLARE_STATIC_KEY_FALSE(br_mst_used);
-static inline bool br_mst_is_enabled(struct net_bridge *br)
+static inline bool br_mst_is_enabled(const struct net_bridge_port *p)
 {
+	/* check the port's vlan group to avoid racing with port deletion */
 	return static_branch_unlikely(&br_mst_used) &&
-		br_opt_get(br, BROPT_MST_ENABLED);
+	       br_opt_get(p->br, BROPT_MST_ENABLED) &&
+	       rcu_access_pointer(p->vlgrp);
 }
 
 int br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state,
@@ -1952,8 +1954,9 @@ int br_mst_fill_info(struct sk_buff *skb,
 		     const struct net_bridge_vlan_group *vg);
 int br_mst_process(struct net_bridge_port *p, const struct nlattr *mst_attr,
 		   struct netlink_ext_ack *extack);
+void br_mst_uninit(struct net_bridge *br);
 #else
-static inline bool br_mst_is_enabled(struct net_bridge *br)
+static inline bool br_mst_is_enabled(const struct net_bridge_port *p)
 {
 	return false;
 }
@@ -1987,6 +1990,10 @@ static inline int br_mst_process(struct net_bridge_port *p,
 {
 	return -EOPNOTSUPP;
 }
+
+static inline void br_mst_uninit(struct net_bridge *br)
+{
+}
 #endif
 
 struct nf_br_ops {