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

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


From: Tom Parkin <redacted>

[ Upstream commit 789336360e0a2aeb9750c16ab704a02cbe035e9e ]

When creating an L2TPv3 Ethernet session, if register_netdev() should fail for
any reason (for example, automatic naming for "l2tpeth%d" interfaces hits the
32k-interface limit), the netdev is freed in the error path.  However, the
l2tp_eth_sess structure's dev pointer is left uncleared, and this results in
l2tp_eth_delete() then attempting to unregister the same netdev later in the
session teardown.  This results in an oops.

To avoid this, clear the session dev pointer in the error path.

Signed-off-by: Tom Parkin <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/l2tp/l2tp_eth.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c

@@ -269,6 +269,7 @@ static int l2tp_eth_create(struct net *n
 
 out_del_dev:
 	free_netdev(dev);
+	spriv->dev = NULL;
 out_del_session:
 	l2tp_session_delete(session);
 out: