Messages in this thread | | | Subject | Re: [PATCH] Sample fix for hyperthread exploit | From | Arjan van de Ven <> | Date | Wed, 01 Jun 2005 21:29:07 +0200 |
| |
On Wed, 2005-06-01 at 10:25 -0700, Chris Wright wrote: > * Con Kolivas (kernel@kolivas.org) wrote: > > On Wed, 1 Jun 2005 22:06, Arjan van de Ven wrote: > > > > Comments? > > > > > > I don't think it's really worth it, but if you go this way I'd rather do > > > this via a prctl() so that apps can tell the kernel "I'd like to run > > > exclusive on a core". That'd be much better than blindly isolating all > > > applications. > > > > I agree, and this is where we (could) implement the core isolation. I'm still > > under the impression (as you appear to be) that this theoretical exploit is > > not worth trying to work around. > > 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.
ptrace-ability goes wonky the moment the "secret bearing" thread revokes something that would make ptrace be denied consequently ... means we'd have to find all those cases and make all of them bump the other app of the cpu. smells too complex to me for such a rare event -> hard to get fail proof.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |