net: l2tp_eth: fix kernel panic on rmmod l2tp_eth

We must prevent module unloading if some devices are still attached to
l2tp_eth driver.

Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: Denys Fedoryshchenko <[email protected]>
Tested-by: Denys Fedoryshchenko <[email protected]>
Cc: James Chapman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 443591d629caadff0da53b2c861b8748e61edf7e..185f12f4a5fa21a90bbce5641b7d751722d8c9ca 100644 (file)
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -162,6 +162,7 @@ static void l2tp_eth_delete(struct l2tp_session *session)
                if (dev) {
                        unregister_netdev(dev);
                        spriv->dev = NULL;
+                       module_put(THIS_MODULE);
                }
        }
 }
@@ -249,6 +250,7 @@ static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p
        if (rc < 0)
                goto out_del_dev;
 
+       __module_get(THIS_MODULE);
        /* Must be done after register_netdev() */
        strlcpy(session->ifname, dev->name, IFNAMSIZ);