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: <f42d25409c8642d9beced75f3c314452@AcuMS.aculab.com>
Date:   Wed, 8 Apr 2020 11:17:43 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Jan Kiszka' <jan.kiszka@...mens.com>,
        Peter Zijlstra <peterz@...radead.org>
CC:     Steven Rostedt <rostedt@...dmis.org>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "hch@...radead.org" <hch@...radead.org>,
        "sean.j.christopherson@...el.com" <sean.j.christopherson@...el.com>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "bp@...en8.de" <bp@...en8.de>, "hpa@...or.com" <hpa@...or.com>,
        "x86@...nel.org" <x86@...nel.org>,
        "kenny@...ix.com" <kenny@...ix.com>,
        "jeyu@...nel.org" <jeyu@...nel.org>,
        "rasmus.villemoes@...vas.dk" <rasmus.villemoes@...vas.dk>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "fenghua.yu@...el.com" <fenghua.yu@...el.com>,
        "xiaoyao.li@...el.com" <xiaoyao.li@...el.com>,
        "nadav.amit@...il.com" <nadav.amit@...il.com>,
        "thellstrom@...are.com" <thellstrom@...are.com>,
        "tony.luck@...el.com" <tony.luck@...el.com>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "jannh@...gle.com" <jannh@...gle.com>,
        "keescook@...omium.org" <keescook@...omium.org>,
        "dcovelli@...are.com" <dcovelli@...are.com>,
        "mhiramat@...nel.org" <mhiramat@...nel.org>,
        Wolfgang Mauerer <wolfgang.mauerer@...-regensburg.de>
Subject: RE: [PATCH 4/4] x86,module: Detect CRn and DRn manipulation

From: Jan Kiszka 
> Sent: 08 April 2020 12:13

> 
> On 08.04.20 11:25, David Laight wrote:
> > From: Jan Kiszka
> >> Sent: 08 April 2020 09:59
> > ...
> >> At the risk of cutting our own branch off: That's not the firmware
> >> loader, it's ioremap with PAGE_KERNEL_EXEC.
> >
> > You could link the 'blob' into the .text part of a normal
> > kernel module and then load that.
> 
> Sure, also possible. Was just more convenient so far to replace the
> hypervisor binary without having to recompile the driver module.

I was thinking of a separate module that contained nothing else.
If it depended on the driver it's 'init' function could call back
into the driver code to pass an entrypoint array (etc).

You can easily to a version check at that point as well.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)