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Subject: Re: [PATCH] vsprintf: Prevent NULL dereference using %pNF
From: Joe Perches <joe@perches.com>
To: David Miller <davem@davemloft.net>
Cc: mirq-linux@rere.qmqm.pl, linux-kernel@vger.kernel.org
Date: Tue, 17 Jan 2012 10:54:56 -0800
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On Tue, 2012-01-17 at 13:52 -0500, David Miller wrote:
> From: Joe Perches <joe@perches.com>
> Date: Tue, 17 Jan 2012 10:51:13 -0800
> 
> > On Tue, 2012-01-17 at 13:46 -0500, David Miller wrote:
> >> From: Joe Perches <joe@perches.com>
> >> Date: Tue, 17 Jan 2012 10:37:13 -0800
> >> > Passing NULL to %pNF is done in skb_gso_segment
> >> > which could be dereferenced.
> >> skb_gso_segment() should be fixed instead.
> > 
> > Maybe.  Dereferencing NULL is bad form.
> 
> We don't check for NULL for IPV4 or IPV6 addresses,

Because we don't pass NULL addresses.

> no reason
> to treat this any differently.

A NULL address is specifically passed here.

> Either do it for all %pX things, or none of them.

Maybe.