l2tp: fix l2tp_eth module loading

commit 9f775ead5e570e7e19015b9e4e2f3dd6e71a5935 upstream.

The l2tp_eth module crashes if its netlink callbacks are run when the
pernet data aren't initialised.

We should normally register_pernet_device() before the genl callbacks.
However, the pernet data only maintain a list of l2tpeth interfaces,
and this list is never used. So let's just drop pernet handling
instead.

Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 683fa79..ec1148c 100644 (file)
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -39,7 +39,6 @@ struct l2tp_eth {
        struct net_device       *dev;
        struct sock             *tunnel_sock;
        struct l2tp_session     *session;
-       struct list_head        list;
 };
 
 /* via l2tp_session_priv() */
@@ -47,17 +46,6 @@ struct l2tp_eth_sess {
        struct net_device       *dev;
 };
 
-/* per-net private data for this module */
-static unsigned int l2tp_eth_net_id;
-struct l2tp_eth_net {
-       struct list_head l2tp_eth_dev_list;
-       spinlock_t l2tp_eth_lock;
-};
-
-static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
-{
-       return net_generic(net, l2tp_eth_net_id);
-}
 
 static int l2tp_eth_dev_init(struct net_device *dev)
 {
@@ -72,12 +60,6 @@ static int l2tp_eth_dev_init(struct net_device *dev)
 
 static void l2tp_eth_dev_uninit(struct net_device *dev)
 {
-       struct l2tp_eth *priv = netdev_priv(dev);
-       struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev));
-
-       spin_lock(&pn->l2tp_eth_lock);
-       list_del_init(&priv->list);
-       spin_unlock(&pn->l2tp_eth_lock);
        dev_put(dev);
 }
 
@@ -193,7 +175,6 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
        struct l2tp_eth *priv;
        struct l2tp_eth_sess *spriv;
        int rc;
-       struct l2tp_eth_net *pn;
 
        if (cfg->ifname) {
                dev = dev_get_by_name(net, cfg->ifname);
@@ -228,7 +209,6 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
        priv = netdev_priv(dev);
        priv->dev = dev;
        priv->session = session;
-       INIT_LIST_HEAD(&priv->list);
 
        priv->tunnel_sock = tunnel->sock;
        session->recv_skb = l2tp_eth_dev_recv;
@@ -249,10 +229,6 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
        strlcpy(session->ifname, dev->name, IFNAMSIZ);
 
        dev_hold(dev);
-       pn = l2tp_eth_pernet(dev_net(dev));
-       spin_lock(&pn->l2tp_eth_lock);
-       list_add(&priv->list, &pn->l2tp_eth_dev_list);
-       spin_unlock(&pn->l2tp_eth_lock);
 
        return 0;
 
@@ -265,22 +241,6 @@ out:
        return rc;
 }
 
-static __net_init int l2tp_eth_init_net(struct net *net)
-{
-       struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
-
-       INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
-       spin_lock_init(&pn->l2tp_eth_lock);
-
-       return 0;
-}
-
-static struct pernet_operations l2tp_eth_net_ops = {
-       .init = l2tp_eth_init_net,
-       .id   = &l2tp_eth_net_id,
-       .size = sizeof(struct l2tp_eth_net),
-};
-
 
 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
        .session_create = l2tp_eth_create,
@@ -294,25 +254,18 @@ static int __init l2tp_eth_init(void)
 
        err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
        if (err)
-               goto out;
-
-       err = register_pernet_device(&l2tp_eth_net_ops);
-       if (err)
-               goto out_unreg;
+               goto err;
 
        printk(KERN_INFO "L2TP ethernet pseudowire support (L2TPv3)\n");
 
        return 0;
 
-out_unreg:
-       l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
-out:
+err:
        return err;
 }
 
 static void __exit l2tp_eth_exit(void)
 {
-       unregister_pernet_device(&l2tp_eth_net_ops);
        l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
 }