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Subject: Re: [PATCH 2/6] autofs4 - remove string terminator check
From: Ian Kent <raven@themaw.net>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
       autofs@linux.kernel.org
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Date: Tue, 28 Oct 2008 10:02:17 +0900
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This response is a bit confusing, let me try to fix that.

On Tue, 2008-10-28 at 09:27 +0900, Ian Kent wrote:
> On Mon, 2008-10-27 at 13:31 -0700, Andrew Morton wrote:
> > On Thu, 23 Oct 2008 10:35:22 +0800
> > Ian Kent <raven@themaw.net> wrote:
> > 
> > > Remove unnecessary string terminator check.
> > 
> > Why is it unnecessary?
> > 
> > Does this change alter behaviour in any way?
> > 
> > Does it fix a bug?
> 
> Umm .... it was done in response to your comment, quoted below ...
> 
<quote>
> > +/*
> > + * Check a string doesn't overrun the chunk of
> > + * memory we copied from user land.
> > + */
> > +static int invalid_str(char *str, void *end)
> > +{
> > +     while ((void *) str <= end)
> > +             if (!*str++)
> > +                     return 0;
> > +     return -EINVAL;
> > +}
> 
> What is this?  We copy strings in from userspace in 10000 different
> places without needing checks such as this?
</quote>