lkml.org 
[lkml]   [2018]   [Jan]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6 11/10] x86/retpoline: Avoid return buffer underflows on context switch
> So I was really hoping that in places like context switching etc, we'd
> be able to instead effectively kill off any exploits by clearing
> registers.
>
> That should make it pretty damn hard to then find a matching "gadget"
> that actually does anything interesting/powerful.
>
> Together with Spectre already being pretty hard to take advantage of,
> and the eBPF people making those user-proivided gadgets inaccessible,
> it really should be a pretty powerful fix.
>
> Hmm?

Essentially the RSB are hidden registers, and the only way to clear them
is the FILL_RETURN_BUFFER sequence. I don't see how clearing anything else
would help?

-Andi

\
 
 \ /
  Last update: 2018-01-14 23:18    [W:0.102 / U:3.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site