From: Eric Dumazet <edumazet@google.com>
Date: Thu, 10 Jan 2013 08:32:45 +0000 (+0000)
Subject: veth: fix a NULL deref in netif_carrier_off
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=2efd32ee1b60b0b31404ca47c1ce70e5a5d24ebc;p=deliverable%2Flinux.git

veth: fix a NULL deref in netif_carrier_off

In commit d0e2c55e7c94 (veth: avoid a NULL deref in veth_stats_one)
we now clear the peer pointers in veth_dellink()

veth_close() must therefore make sure the peer pointer is set.

Reported-by: Tom Parkin <tom.parkin@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 0f71a4fe506a..e1da42aaf9de 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -206,9 +206,11 @@ static int veth_open(struct net_device *dev)
 static int veth_close(struct net_device *dev)
 {
 	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
 
 	netif_carrier_off(dev);
-	netif_carrier_off(rtnl_dereference(priv->peer));
+	if (peer)
+		netif_carrier_off(peer);
 
 	return 0;
 }