From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jarek Poplawski <jarkao2@gmail.com>
Subject: Re: [patch] hamradio: avoid null deref
Date: Wed, 23 Dec 2009 18:47:46 +0100
Message-ID: <4B3257C2.2050500@gmail.com>
References: <20091223132550.GD17923@bicker>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
To: Dan Carpenter <error27@gmail.com>
Return-path: <linux-kernel-owner+glk-linux-kernel-3=40m.gmane.org-S1756570AbZLWRrx@vger.kernel.org>
In-Reply-To: <20091223132550.GD17923@bicker>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org

Dan Carpenter wrote, On 12/23/2009 02:25 PM:

> If dev == NULL we shouldn't dereference it.
> 
> Signed-off-by: Dan Carpenter <error27@gmail.com>
> 
> --- orig/drivers/net/hamradio/bpqether.c	2009-12-22 23:58:56.000000000 +0200
> +++ devel/drivers/net/hamradio/bpqether.c	2009-12-22 23:59:46.000000000 +0200
> @@ -283,7 +283,6 @@ static netdev_tx_t bpq_xmit(struct sk_bu
>  	bpq = netdev_priv(dev);
>  
>  	if ((dev = bpq_get_ether_dev(dev)) == NULL) {
> -		dev->stats.tx_dropped++;

Why not use a separate variable for another dev? This stat
should be helpful for debugging.

Jarek P.

>  		kfree_skb(skb);
>  		return NETDEV_TX_OK;
>  	}