Re: [RFC PATCH v2 2/6] x86/arch_prctl: add ARCH_GET_NOPTI and ARCH_SET_NOPTI to enable/disable PTI

From: Kees Cook
Date: Tue Jan 09 2018 - 16:34:14 EST


On Tue, Jan 9, 2018 at 1:26 PM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> 2.Turning off PTI is, in general, a terrible idea. It totally breaks
> any semblance of a security model on a Meltdown-affected CPU. So I
> think we should require CAP_SYS_RAWIO *and* that the system is booted
> with pti=allow_optout or something like that.

Agreed, this shouldn't be default-available. Besides, your most
trusted processes are the ones most likely to be targeted for attack.
:(

-Kees

--
Kees Cook
Pixel Security