[PATCH 4.13 046/160] l2tp: fix l2tp_eth module loading

From: Greg Kroah-Hartman
Date: Tue Oct 10 2017 - 16:03:27 EST


4.13-stable review patch. If anyone has any objections, please let me know.

------------------

From: Guillaume Nault <g.nault@xxxxxxxxxxxx>


[ Upstream commit 9f775ead5e570e7e19015b9e4e2f3dd6e71a5935 ]

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@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/l2tp/l2tp_eth.c | 51 ++-------------------------------------------------
1 file changed, 2 insertions(+), 49 deletions(-)

--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -44,7 +44,6 @@ struct l2tp_eth {
struct net_device *dev;
struct sock *tunnel_sock;
struct l2tp_session *session;
- struct list_head list;
atomic_long_t tx_bytes;
atomic_long_t tx_packets;
atomic_long_t tx_dropped;
@@ -58,17 +57,6 @@ 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)
{
@@ -84,12 +72,6 @@ static int l2tp_eth_dev_init(struct net_

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);
}

@@ -272,7 +254,6 @@ static int l2tp_eth_create(struct net *n
struct l2tp_eth *priv;
struct l2tp_eth_sess *spriv;
int rc;
- struct l2tp_eth_net *pn;

tunnel = l2tp_tunnel_find(net, tunnel_id);
if (!tunnel) {
@@ -310,7 +291,6 @@ static int l2tp_eth_create(struct net *n
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;
@@ -331,10 +311,6 @@ static int l2tp_eth_create(struct net *n
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;

@@ -347,22 +323,6 @@ 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,
@@ -376,25 +336,18 @@ 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;

pr_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);
}