linux-kernel - Re: umip: AMD Ryzen 3900X, pagefault after emulate SLDT/SIDT instruction

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <a0f55ad9-f85b-3b2a-e75d-43d4a54063fb@zytor.com>
Date:   Tue, 19 May 2020 17:17:28 -0700
From:   "H. Peter Anvin" <hpa@...or.com>
To:     Andreas Rammhold <andi@...much.email>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org,
        Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Babu Moger <Babu.Moger@....com>,
        Kefeng Wang <wangkefeng.wang@...wei.com>,
        Jason Yan <yanaijie@...wei.com>,
        Brendan Shanks <bshanks@...eweavers.com>,
        linux-kernel@...r.kernel.org
Subject: Re: umip: AMD Ryzen 3900X, pagefault after emulate SLDT/SIDT
 instruction

On 2020-05-19 07:38, Andreas Rammhold wrote:
> Hi,
> 
> I've been running into a weird problem with UMIP on a current Ryzen
> 3900x with kernel 5.6.11 where a process receives a page fault after the
> kernel handled the SLDT (or SIDT) instruction (emulation).
> 
> The program I am running is run through WINE in 32bit mode and tries to
> figure out if it is running in a VMWare machine by comparing the results
> of SLDT against well known constants (basically as shown in the
> [example] linked below).
> 

Extremely weird. What is it expecting to happen -- or rather, what do you
*want* it to do?

	-hpa