linux-kernel - Re: [PATCH 4/4] x86,module: Detect CRn and DRn manipulation

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: <aa7a2547-9670-d04f-4ca0-ab52abf30441@siemens.com>
Date:   Wed, 8 Apr 2020 10:59:02 +0200
From:   Jan Kiszka <jan.kiszka@...mens.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Steven Rostedt <rostedt@...dmis.org>, tglx@...utronix.de,
        linux-kernel@...r.kernel.org, hch@...radead.org,
        sean.j.christopherson@...el.com, mingo@...hat.com, bp@...en8.de,
        hpa@...or.com, x86@...nel.org, kenny@...ix.com, jeyu@...nel.org,
        rasmus.villemoes@...vas.dk, pbonzini@...hat.com,
        fenghua.yu@...el.com, xiaoyao.li@...el.com, nadav.amit@...il.com,
        thellstrom@...are.com, tony.luck@...el.com,
        gregkh@...uxfoundation.org, jannh@...gle.com,
        keescook@...omium.org, David.Laight@...lab.com,
        dcovelli@...are.com, mhiramat@...nel.org,
        Wolfgang Mauerer <wolfgang.mauerer@...-regensburg.de>
Subject: Re: [PATCH 4/4] x86,module: Detect CRn and DRn manipulation

On 08.04.20 10:51, Peter Zijlstra wrote:
> On Wed, Apr 08, 2020 at 07:58:53AM +0200, Jan Kiszka wrote:
>> On 07.04.20 23:48, Steven Rostedt wrote:
> 
>>> Hmm, wont this break jailhouse?
> 
> Breaking it isn't a problem, it's out of tree and it should be fixable.
> 
>> Yes, possibly. We load the hypervisor binary via request_firmware into
>> executable memory and then jump into it. So most of the "suspicious" code is
> 
> W.T.H. does the firmware loader have the ability to give executable
> memory? We need to kill that too. /me goes find.
> 

At the risk of cutting our own branch off: That's not the firmware 
loader, it's ioremap with PAGE_KERNEL_EXEC.

Jan

-- 
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux