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Date: Tue, 17 Jul 2012 09:36:35 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
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To: David Rientjes <rientjes@google.com>
cc: Shuah Khan <shuah.khan@hp.com>, Pekka Enberg <penberg@kernel.org>,
        glommer@parallels.com, js1304@gmail.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, shuahkhan@gmail.com
Subject: Re: [PATCH TRIVIAL] mm: Fix build warning in kmem_cache_create()
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On Mon, 16 Jul 2012, David Rientjes wrote:

> > The kernel cannot check everything and will blow up in unexpected ways if
> > someone codes something stupid. There are numerous debugging options that
> > need to be switched on to get better debugging information to investigate
> > deper. Adding special code to replicate these checks is bad.
> >
>
> Disagree, CONFIG_SLAB does not blow up for a NULL name string and just
> corrupts userspace.

Ohh.. So far we only had science fiction. Now kernel fiction.... If you
could corrupt userspace using sysfs with a NULL string then you'd first
need to fix sysfs support.

And if you really want to be totally safe then I guess you need to audit
the kernel and make sure that every core kernel function that takes a
string argument does check for it to be NULL just in case.