[ 52/66] l2tp: fix oops in l2tp_eth_create() error path

From: Greg Kroah-Hartman
Date: Wed Nov 14 2012 - 23:31:14 EST


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

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


From: Tom Parkin <tparkin@xxxxxxxxxxx>

[ 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 <tparkin@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/l2tp/l2tp_eth.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -290,6 +290,7 @@ 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:


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