Re: [PATCH] Sample fix for hyperthread exploit

From: Amit Shah
Date: Thu Jun 02 2005 - 01:33:42 EST


Ingo Molnar wrote:

>
> * Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:
>
>> > Also, uid is not sufficient. Something more comprehensive (like
>> > ability to ptrace) would be appropriate.
>>
>> I would go a lot simpler. App says "I want exclusivity" via pctl and
>> NOTHING runs on the other half. Well maybe with exceptions of
>> processes that share the mm with the exclusive one (in practice
>> "threads") since those could just read the memory anyway.
>
> this has the disadvantage of needing changes in the security apps.
> Basing this off the uid (or the ability to ptrace) makes it at least
> automatic - but introduces a permanent penalty not only on multiuser
> boxes, but on basically any server box that runs multiple services.

Can this be not limited to just not running any other process on the same
(SMT-enabled) processor (precondition being ability to ptrace)?

Amit.
--
Amit Shah
http://amitshah.net/

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