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>

1 files changed, 3 insertions, 1 deletions

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;
 }