[Info-vax] Alpha and no-execute, was: Re: An old VMS vulnerability, was: Re: Calling standards, was: Re:

[Simon Clubley]

On 2016-11-29, Bob Koehler <koehler at eisner.nospam.decuserve.org> wrote:
> In article <o1i312$vle$1 at dont-email.me>, Simon Clubley <clubley at remove_me.eisner.decus.org-Earth.UFP> writes:
>> 
>> One way to stop that as an attack vector is to make sure that the
>> memory pages allocated to the logical name tables are marked as
>> no-execute. I don't know where you stored the shellcode in your
>> version, but I also hope that those memory pages are now no-execute
>> in VMS as well.
>
>    No-execute is a problem, since VMS still runs on VAXen and Alphas
>    that don't enforce no-execute.  IIRC IA64 does support it.  Don't
>    know about x86, but I thought current generations do.
>

Did early versions of the Alpha architecture not support no-execute ?

Somehow, I had thought it was available on all versions of the Alpha
architecture.

It's also the kind of thing that should be buried inside the HAL
(or what passes for the HAL in VMS) so that it would be a no-op
on architectures which don't support no-execute.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
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