From: Pavel Emelyanov <xemul@openvz.org>
Date: Mon, 11 May 2009 00:36:35 +0000 (+0000)
Subject: netpoll: don't dereference NULL dev from np
X-Git-Tag: v2.6.30-rc7~20^2~16
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=5e392739d6ab72f7c35040aa07f4097904bce6e7;p=~shefty%2Frdma-dev.git

netpoll: don't dereference NULL dev from np

It looks like the dev in netpoll_poll can be NULL - at lease it's
checked at the function beginning. Thus the dev->netde_ops dereference
looks dangerous.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index b5873bdff61..64f51eec657 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -175,9 +175,13 @@ static void service_arp_queue(struct netpoll_info *npi)
 void netpoll_poll(struct netpoll *np)
 {
 	struct net_device *dev = np->dev;
-	const struct net_device_ops *ops = dev->netdev_ops;
+	const struct net_device_ops *ops;
+
+	if (!dev || !netif_running(dev))
+		return;
 
-	if (!dev || !netif_running(dev) || !ops->ndo_poll_controller)
+	ops = dev->netdev_ops;
+	if (!ops->ndo_poll_controller)
 		return;
 
 	/* Process pending work on NIC */