lkml.org 
[lkml]   [2017]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 00/23] KAISER: unmap most of the kernel from userspace page tables
Hi!

> KAISER makes it harder to defeat KASLR, but makes syscalls and
> interrupts slower. These patches are based on work from a team at
> Graz University of Technology posted here[1]. The major addition is
> support for Intel PCIDs which builds on top of Andy Lutomorski's PCID
> work merged for 4.14. PCIDs make KAISER's overhead very reasonable
> for a wide variety of use cases.

Is it useful?

> Full Description:
>
> KAISER is a countermeasure against attacks on kernel address
> information. There are at least three existing, published,
> approaches using the shared user/kernel mapping and hardware features
> to defeat KASLR. One approach referenced in the paper locates the
> kernel by observing differences in page fault timing between
> present-but-inaccessable kernel pages and non-present pages.

I mean... evil userspace will still be able to determine kernel's
location using cache aliasing effects, right?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2017-11-22 17:19    [W:0.188 / U:38.496 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site