Messages in this thread | | | Subject | Re: [RFC PATCH v2 6/6] x86/entry/pti: don't switch PGD on when pti_disable is set | From | Dave Hansen <> | Date | Thu, 11 Jan 2018 10:57:51 -0800 |
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On 01/11/2018 10:51 AM, Linus Torvalds wrote: > On Thu, Jan 11, 2018 at 10:38 AM, Dave Hansen > <dave.hansen@linux.intel.com> wrote: >> On 01/11/2018 10:32 AM, Josh Poimboeuf wrote: >>>> hmm. Exposing cr3 to user space will make it trivial for user process >>>> to know whether kpti is active. Not sure how exploitable such >>>> information leak. >>> It's already trivial to detect PTI from user space. >> Do tell. > One way to do it is to just run the attack, and see if you get something.
Not judging how trivial (or not) the attack is, I was hoping for something that was *not* the attack itself. :)
I'd love to have a tool that tells you for sure "KPTI enabled or not", but I'd also love to have it be something I can easily distribute without it being handled like a WMD.
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