diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c
index 05ba65042b5f..6be9fed50ed5 100644
--- a/drivers/net/dsa/sja1105/sja1105_main.c
+++ b/drivers/net/dsa/sja1105/sja1105_main.c
@@ -120,12 +120,21 @@ static int sja1105_commit_pvid(struct dsa_switch *ds, int port)
 	if (rc)
 		return rc;
 
-	vlan = priv->static_config.tables[BLK_IDX_VLAN_LOOKUP].entries;
+	/* Only force dropping of untagged packets when the port is under a
+	 * VLAN-aware bridge. When the tag_8021q pvid is used, we are
+	 * deliberately removing the RX VLAN from the port's VMEMB_PORT list,
+	 * to prevent DSA tag spoofing from the link partner. Untagged packets
+	 * are the only ones that should be received with tag_8021q, so
+	 * definitely don't drop them.
+	 */
+	if (pvid == priv->bridge_pvid[port]) {
+		vlan = priv->static_config.tables[BLK_IDX_VLAN_LOOKUP].entries;
 
-	match = sja1105_is_vlan_configured(priv, pvid);
+		match = sja1105_is_vlan_configured(priv, pvid);
 
-	if (match < 0 || !(vlan[match].vmemb_port & BIT(port)))
-		drop_untagged = true;
+		if (match < 0 || !(vlan[match].vmemb_port & BIT(port)))
+			drop_untagged = true;
+	}
 
 	return sja1105_drop_untagged(ds, port, drop_untagged);
 }
@@ -2343,7 +2352,7 @@ int sja1105_vlan_filtering(struct dsa_switch *ds, int port, bool enabled,
 }
 
 static int sja1105_vlan_add(struct sja1105_private *priv, int port, u16 vid,
-			    u16 flags)
+			    u16 flags, bool allowed_ingress)
 {
 	struct sja1105_vlan_lookup_entry *vlan;
 	struct sja1105_table *table;
@@ -2365,7 +2374,12 @@ static int sja1105_vlan_add(struct sja1105_private *priv, int port, u16 vid,
 	vlan[match].type_entry = SJA1110_VLAN_D_TAG;
 	vlan[match].vlanid = vid;
 	vlan[match].vlan_bc |= BIT(port);
-	vlan[match].vmemb_port |= BIT(port);
+
+	if (allowed_ingress)
+		vlan[match].vmemb_port |= BIT(port);
+	else
+		vlan[match].vmemb_port &= ~BIT(port);
+
 	if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
 		vlan[match].tag_port &= ~BIT(port);
 	else
@@ -2437,7 +2451,7 @@ static int sja1105_bridge_vlan_add(struct dsa_switch *ds, int port,
 	if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
 		flags = 0;
 
-	rc = sja1105_vlan_add(priv, port, vlan->vid, flags);
+	rc = sja1105_vlan_add(priv, port, vlan->vid, flags, true);
 	if (rc)
 		return rc;
 
@@ -2467,9 +2481,16 @@ static int sja1105_dsa_8021q_vlan_add(struct dsa_switch *ds, int port, u16 vid,
 				      u16 flags)
 {
 	struct sja1105_private *priv = ds->priv;
+	bool allowed_ingress = true;
 	int rc;
 
-	rc = sja1105_vlan_add(priv, port, vid, flags);
+	/* Prevent attackers from trying to inject a DSA tag from
+	 * the outside world.
+	 */
+	if (dsa_is_user_port(ds, port))
+		allowed_ingress = false;
+
+	rc = sja1105_vlan_add(priv, port, vid, flags, allowed_ingress);
 	if (rc)
 		return rc;