All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Micah Gruber <micah.gruber@gmail.com>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	jgarzik@pobox.com, Grant Grundler <grundler@parisc-linux.org>
Subject: Re: [CORRECTION][PATCH] Fix a potential NULL pointer dereference in uli526x_interrupt() in drivers/net/tulip/uli526x.c
Date: Thu, 13 Sep 2007 02:03:46 -0700	[thread overview]
Message-ID: <20070913020346.979647c1.akpm@linux-foundation.org> (raw)
In-Reply-To: <46DD13CE.6010905@gmail.com>

On Tue, 04 Sep 2007 16:14:06 +0800 Micah Gruber <micah.gruber@gmail.com> wrote:

> This patch fixes a potential null dereference bug where we dereference dev before a null check. This patch simply moves the dereferencing after the null check.
> 
> Signed-off-by: Micah Gruber <micah.gruber@gmail.com>
> ---
> 
> --- a/drivers/net/tulip/uli526x.c
> +++ b/drivers/net/tulip/uli526x.c
> @@ -663,7 +663,7 @@
>  {
>  	struct net_device *dev = dev_id;
>  	struct uli526x_board_info *db = netdev_priv(dev);
> -	unsigned long ioaddr = dev->base_addr;
> +	unsigned long ioaddr;
>  	unsigned long flags;
>  
>  	if (!dev) {
> @@ -671,6 +671,8 @@
>  		return IRQ_NONE;
>  	}
>  
> +	ioaddr = dev->base_addr;
> +
>  	spin_lock_irqsave(&db->lock, flags);
>  	outl(0, ioaddr + DCR7);
> 

I suspect the fix we want is:


--- a/drivers/net/tulip/uli526x.c~fix-a-potential-null-pointer-dereference-in-uli526x_interrupt
+++ a/drivers/net/tulip/uli526x.c
@@ -666,11 +666,6 @@ static irqreturn_t uli526x_interrupt(int
 	unsigned long ioaddr = dev->base_addr;
 	unsigned long flags;
 
-	if (!dev) {
-		ULI526X_DBUG(1, "uli526x_interrupt() without DEVICE arg", 0);
-		return IRQ_NONE;
-	}
-
 	spin_lock_irqsave(&db->lock, flags);
 	outl(0, ioaddr + DCR7);
 
_


  parent reply	other threads:[~2007-09-13  9:04 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-09-04  8:14 [CORRECTION][PATCH] Fix a potential NULL pointer dereference in uli526x_interrupt() in drivers/net/tulip/uli526x.c Micah Gruber
2007-09-07 23:20 ` Jeff Garzik
2007-09-13  9:03 ` Andrew Morton [this message]
2007-09-13  9:03   ` Kyle McMartin
2007-09-13 14:16   ` Jeff Garzik

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20070913020346.979647c1.akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=grundler@parisc-linux.org \
    --cc=jgarzik@pobox.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=micah.gruber@gmail.com \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.