Re: [PATCH] Sample fix for hyperthread exploit

From: Ingo Molnar
Date: Wed Jun 01 2005 - 21:52:42 EST



* 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.

Ingo
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