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

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

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit a06998b88b1651c5f71c0e35f528bf2057188ead ]

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

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Denys Fedoryshchenko <redacted>
Tested-by: Denys Fedoryshchenko <redacted>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <redacted>
---
 net/l2tp/l2tp_eth.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index d2726a7..3c55f63 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c

@@ -167,6 +167,7 @@ static void l2tp_eth_delete(struct l2tp_session *session)
 		if (dev) {
 			unregister_netdev(dev);
 			spriv->dev = NULL;
+			module_put(THIS_MODULE);
 		}
 	}
 }

@@ -254,6 +255,7 @@ 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);