Patchwork [201/241] l2tp: fix oops in l2tp_eth_create() error path

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Submitter Herton Ronaldo Krzesinski
Date Dec. 13, 2012, 1:59 p.m.
Message ID <1355407206-17100-202-git-send-email-herton.krzesinski@canonical.com>
Download mbox | patch
Permalink /patch/206047/
State New
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Comments

Herton Ronaldo Krzesinski - Dec. 13, 2012, 1:59 p.m.
3.5.7.2 -stable review patch.  If anyone has any objections, please let me know.

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

From: Tom Parkin <tparkin@katalix.com>

commit 789336360e0a2aeb9750c16ab704a02cbe035e9e upstream.

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@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 net/l2tp/l2tp_eth.c |    1 +
 1 file changed, 1 insertion(+)

Patch

diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 94840d8..80196f3 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -285,6 +285,7 @@  static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p
 
 out_del_dev:
 	free_netdev(dev);
+	spriv->dev = NULL;
 out_del_session:
 	l2tp_session_delete(session);
 out: