bridge: fix hang on removal of bridge via netlink

[ Upstream commit 1ce5cce895309862d2c35d922816adebe094fe4a ]

Need to cleanup bridge device timers and ports when being bridge
device is being removed via netlink.

This fixes the problem of observed when doing:
 ip link add br0 type bridge
 ip link set dev eth1 master br0
 ip link set br0 up
 ip link del br0

which would cause br0 to hang in unregister_netdev because
of leftover reference count.

Reported-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 7 insertions, 4 deletions

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 6f156c19999..449087373d8 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -161,9 +161,10 @@ static void del_nbp(struct net_bridge_port *p)
         call_rcu(&p->rcu, destroy_nbp_rcu);
 }
 
-/* called with RTNL */
-static void del_br(struct net_bridge *br, struct list_head *head)
+/* Delete bridge device */
+void br_dev_delete(struct net_device *dev, struct list_head *head)
 {
+        struct net_bridge *br = netdev_priv(dev);
         struct net_bridge_port *p, *n;
 
         list_for_each_entry_safe(p, n, &br->port_list, list) {
@@ -268,7 +269,7 @@ int br_del_bridge(struct net *net, const char *name)
         }
 
         else
-                del_br(netdev_priv(dev), NULL);
+                br_dev_delete(dev, NULL);
 
         rtnl_unlock();
         return ret;
@@ -445,7 +446,7 @@ void __net_exit br_net_exit(struct net *net)
         rtnl_lock();
         for_each_netdev(net, dev)
                 if (dev->priv_flags & IFF_EBRIDGE)
-                        del_br(netdev_priv(dev), &list);
+                        br_dev_delete(dev, &list);
 
         unregister_netdevice_many(&list);
         rtnl_unlock();
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index ffb0dc4cc0e..2c160552568 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -208,6 +208,7 @@ static struct rtnl_link_ops br_link_ops __read_mostly = {
         .priv_size      = sizeof(struct net_bridge),
         .setup          = br_dev_setup,
         .validate       = br_validate,
+        .dellink        = br_dev_delete,
 };
 
 int __init br_netlink_init(void)
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 78cc364997d..857a021deea 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -294,6 +294,7 @@ static inline int br_is_root_bridge(const struct net_bridge *br)
 
 /* br_device.c */
 extern void br_dev_setup(struct net_device *dev);
+extern void br_dev_delete(struct net_device *dev, struct list_head *list);
 extern netdev_tx_t br_dev_xmit(struct sk_buff *skb,
                                struct net_device *dev);
 #ifdef CONFIG_NET_POLL_CONTROLLER