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Subject: Re: [kernel-hardening] Re: [PATCH v3 00/13] Virtually mapped stacks
 with guard pages (x86, core)
From: Rik van Riel <riel@redhat.com>
To: kernel-hardening@lists.openwall.com, Andy Lutomirski <luto@amacapital.net>,
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Date: Tue, 21 Jun 2016 14:19:49 -0400
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On Tue, 2016-06-21 at 11:12 -0700, Kees Cook wrote:
> On Tue, Jun 21, 2016 at 10:27 AM, Andy Lutomirski
> <luto@amacapital.net> wrote:
> > FWIW, it may be a while before this can be enabled in distro
> > kernels.
> > There are some code paths (*cough* crypto users *cough*) that think
> > that calling sg_init_one with a stack address is a reasonable thing
> > to
> > do, and it doesn't work with a vmalloced stack.=C2=A0=C2=A0grsecurity w=
orks
> ... O_o ...
>=20
> Why does it not work on a vmalloced stack??

Because virt_to_page() does not work on vmalloced
memory.

--=20
All Rights Reversed.


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