batman-adv: clean untagged VLAN on netdev registration failure

When an mesh interface is registered, it creates an untagged struct
batadv_meshif_vlan on top of it via the NETDEV_REGISTER notifier. But in
this process, another receiver of this notification can veto the
registration. The netdev registration will be aborted because of this veto.

The register_netdevice() call will try to clean up the net_device using
unregister_netdevice_queue() - which only uses the .priv_destructor to
free private resources. In this situation, .dellink will not be called.

The cleanup of the untagged batadv_meshif_vlan must thefore be done in the
destructor to avoid a leak of this object.

Cc: stable@vger.kernel.org
Fixes: 5d2c05b21337 ("batman-adv: add per VLAN interface attribute framework")
Signed-off-by: Sven Eckelmann <sven@narfation.org>

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 8844e40e6a80345bcdc4149824c2d3be696c963b..67bed3ee77e7e72e67ce0361960620661ddbb798 100644 (file)
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -259,6 +259,7 @@ err_orig:
 void batadv_mesh_free(struct net_device *mesh_iface)
 {
        struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
+       struct batadv_meshif_vlan *vlan;
 
        WRITE_ONCE(bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
 
@@ -273,6 +274,13 @@ void batadv_mesh_free(struct net_device *mesh_iface)
 
        batadv_mcast_free(bat_priv);
 
+       /* destroy the "untagged" VLAN */
+       vlan = batadv_meshif_vlan_get(bat_priv, BATADV_NO_FLAGS);
+       if (vlan) {
+               batadv_meshif_destroy_vlan(bat_priv, vlan);
+               batadv_meshif_vlan_put(vlan);
+       }
+
        /* Free the TT and the originator tables only after having terminated
         * all the other depending components which may use these structures for
         * their purposes.

diff --git a/net/batman-adv/mesh-interface.c b/net/batman-adv/mesh-interface.c
index 0b75234521b6317abbec60e494edb6e44b16adfa..fbfd99268de47e1d83357fb06c2c3ab12666ecfc 100644 (file)
--- a/net/batman-adv/mesh-interface.c
+++ b/net/batman-adv/mesh-interface.c
@@ -595,8 +595,8 @@ int batadv_meshif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
  * @bat_priv: the bat priv with all the mesh interface information
  * @vlan: the object to remove
  */
-static void batadv_meshif_destroy_vlan(struct batadv_priv *bat_priv,
-                                      struct batadv_meshif_vlan *vlan)
+void batadv_meshif_destroy_vlan(struct batadv_priv *bat_priv,
+                               struct batadv_meshif_vlan *vlan)
 {
        /* explicitly remove the associated TT local entry because it is marked
         * with the NOPURGE flag
@@ -1091,22 +1091,13 @@ static int batadv_meshif_newlink(struct net_device *dev,
 static void batadv_meshif_destroy_netlink(struct net_device *mesh_iface,
                                          struct list_head *head)
 {
-       struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
        struct batadv_hard_iface *hard_iface;
-       struct batadv_meshif_vlan *vlan;
 
        while (!list_empty(&mesh_iface->adj_list.lower)) {
                hard_iface = netdev_adjacent_get_private(mesh_iface->adj_list.lower.next);
                batadv_hardif_disable_interface(hard_iface);
        }
 
-       /* destroy the "untagged" VLAN */
-       vlan = batadv_meshif_vlan_get(bat_priv, BATADV_NO_FLAGS);
-       if (vlan) {
-               batadv_meshif_destroy_vlan(bat_priv, vlan);
-               batadv_meshif_vlan_put(vlan);
-       }
-
        unregister_netdevice_queue(mesh_iface, head);
 }
 

diff --git a/net/batman-adv/mesh-interface.h b/net/batman-adv/mesh-interface.h
index 53756c5a45e0471b82a21d3bbc4fd7d6b68924fb..5e1e83e04ffbc6dbb2765b26433084d57f688edc 100644 (file)
--- a/net/batman-adv/mesh-interface.h
+++ b/net/batman-adv/mesh-interface.h
@@ -21,6 +21,8 @@ void batadv_interface_rx(struct net_device *mesh_iface,
 bool batadv_meshif_is_valid(const struct net_device *net_dev);
 extern struct rtnl_link_ops batadv_link_ops;
 int batadv_meshif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid);
+void batadv_meshif_destroy_vlan(struct batadv_priv *bat_priv,
+                               struct batadv_meshif_vlan *vlan);
 void batadv_meshif_vlan_release(struct kref *ref);
 struct batadv_meshif_vlan *batadv_meshif_vlan_get(struct batadv_priv *bat_priv,
                                                  unsigned short vid);