From: Jiri Slaby <jslaby@suse.cz>
Date: Tue, 22 Jun 2010 01:41:36 +0000 (+0000)
Subject: ISDN: hysdn, fix potential NULL dereference
X-Git-Tag: firefly_0821_release~9833^2~1353^2~69
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d41de3c10047d5f0b661593a8f4610a19f87621f;p=firefly-linux-kernel-4.4.55.git

ISDN: hysdn, fix potential NULL dereference

Stanse found that lp is dereferenced earlier than checked for being
NULL in hysdn_rx_netpkt. Move the initialization below the test.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/isdn/hysdn/hysdn_net.c b/drivers/isdn/hysdn/hysdn_net.c
index 72eb92647c1b..feec8d89d719 100644
--- a/drivers/isdn/hysdn/hysdn_net.c
+++ b/drivers/isdn/hysdn/hysdn_net.c
@@ -187,12 +187,13 @@ void
 hysdn_rx_netpkt(hysdn_card * card, unsigned char *buf, unsigned short len)
 {
 	struct net_local *lp = card->netif;
-	struct net_device *dev = lp->dev;
+	struct net_device *dev;
 	struct sk_buff *skb;
 
 	if (!lp)
 		return;		/* non existing device */
 
+	dev = lp->dev;
 	dev->stats.rx_bytes += len;
 
 	skb = dev_alloc_skb(len);