Merge branch 'vlan-QinQ-leak-fix'

Xin Long says:

====================
vlan: fix a netdev refcnt leak for QinQ

This issue can be simply reproduced by:

  # ip link add dummy0 type dummy
  # ip link add link dummy0 name dummy0.1 type vlan id 1
  # ip link add link dummy0.1 name dummy0.1.2 type vlan id 2
  # rmmod 8021q

 unregister_netdevice: waiting for dummy0.1 to become free. Usage count = 1

So as to fix it, adjust vlan_dev_uninit() in Patch 1/1 so that it won't
be called twice for the same device, then do the fix in vlan_dev_uninit()
in Patch 2/2.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net/8021q/vlan.h

@@ -129,6 +129,7 @@ void vlan_dev_set_ingress_priority(const struct net_device *dev,
 				   u32 skb_prio, u16 vlan_prio);
 int vlan_dev_set_egress_priority(const struct net_device *dev,
 				 u32 skb_prio, u16 vlan_prio);
+void vlan_dev_free_egress_priority(const struct net_device *dev);
 int vlan_dev_change_flags(const struct net_device *dev, u32 flag, u32 mask);
 void vlan_dev_get_realdev_name(const struct net_device *dev, char *result,
 			       size_t size);
@@ -139,7 +140,6 @@ int vlan_check_real_dev(struct net_device *real_dev,
 void vlan_setup(struct net_device *dev);
 int register_vlan_dev(struct net_device *dev, struct netlink_ext_ack *extack);
 void unregister_vlan_dev(struct net_device *dev, struct list_head *head);
-void vlan_dev_uninit(struct net_device *dev);
 bool vlan_dev_inherit_address(struct net_device *dev,
 			      struct net_device *real_dev);
 

net/8021q/vlan_dev.c

@@ -622,7 +622,7 @@ static int vlan_dev_init(struct net_device *dev)
 }
 
 /* Note: this function might be called multiple times for the same device. */
-void vlan_dev_uninit(struct net_device *dev)
+void vlan_dev_free_egress_priority(const struct net_device *dev)
 {
 	struct vlan_priority_tci_mapping *pm;
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
@@ -636,6 +636,16 @@ void vlan_dev_uninit(struct net_device *dev)
 	}
 }
 
+static void vlan_dev_uninit(struct net_device *dev)
+{
+	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
+
+	vlan_dev_free_egress_priority(dev);
+
+	/* Get rid of the vlan's reference to real_dev */
+	dev_put_track(vlan->real_dev, &vlan->dev_tracker);
+}
+
 static netdev_features_t vlan_dev_fix_features(struct net_device *dev,
 	netdev_features_t features)
 {
@@ -846,9 +856,6 @@ static void vlan_dev_free(struct net_device *dev)
 
 	free_percpu(vlan->vlan_pcpu_stats);
 	vlan->vlan_pcpu_stats = NULL;
-
-	/* Get rid of the vlan's reference to real_dev */
-	dev_put_track(vlan->real_dev, &vlan->dev_tracker);
 }
 
 void vlan_setup(struct net_device *dev)

net/8021q/vlan_netlink.c

@@ -183,10 +183,11 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
 		return -EINVAL;
 
 	err = vlan_changelink(dev, tb, data, extack);
-	if (!err)
-		err = register_vlan_dev(dev, extack);
 	if (err)
-		vlan_dev_uninit(dev);
+		return err;
+	err = register_vlan_dev(dev, extack);
+	if (err)
+		vlan_dev_free_egress_priority(dev);
 	return err;
 }