Re: Sanitize CPU-state when switching tasks (was sanitize CPU-statewhen switching from virtual-8086 mode to other task)

From: Borislav Petkov
Date: Wed Jan 08 2014 - 14:37:13 EST


On Wed, Jan 08, 2014 at 09:42:40AM -0800, H. Peter Anvin wrote:
> Adding Borislav.
>
> Boris, do you happen to know of any erratum on AMD E-350 which may be
> in play here?

Interesting. Well, nothing looks even remotely related from looking at the F14h
rev guide here:

http://developer.amd.com/wordpress/media/2012/10/47534_14h_Mod_00h-0Fh_Rev_Guide.pdf

Btw, hd (if that is your real name :-)), can you post /proc/cpuinfo? I
think I might have a E-350 here too and I could try to reproduce. Btw,
how exactly do you trigger?

You run FpuStateTaskSwitchShmemXattrHandlersOverwriteWithNullPage.c
first to modify shmem_xattr_handlers and then
ManipulatedXattrHandlerForPrivEscalation.c? You need a 32-bit kernel and
userspace, right? Anything else?

Thanks.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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