linux-kernel - Re: [RFC PATCH v2 10/20] x86: Insure that memory areas are encrypted when possible

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]

Date:   Wed, 14 Sep 2016 09:11:13 -0500
From:   Tom Lendacky <thomas.lendacky@....com>
To:     Borislav Petkov <bp@...en8.de>
CC:     <linux-arch@...r.kernel.org>, <linux-efi@...r.kernel.org>,
        <kvm@...r.kernel.org>, <linux-doc@...r.kernel.org>,
        <x86@...nel.org>, <linux-kernel@...r.kernel.org>,
        <kasan-dev@...glegroups.com>, <linux-mm@...ck.org>,
        <iommu@...ts.linux-foundation.org>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Arnd Bergmann <arnd@...db.de>,
        Jonathan Corbet <corbet@....net>,
        Matt Fleming <matt@...eblueprint.co.uk>,
        Joerg Roedel <joro@...tes.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Ingo Molnar <mingo@...hat.com>,
        Andy Lutomirski <luto@...nel.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Alexander Potapenko <glider@...gle.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Dmitry Vyukov <dvyukov@...gle.com>
Subject: Re: [RFC PATCH v2 10/20] x86: Insure that memory areas are encrypted
 when possible

On 09/12/2016 11:33 AM, Borislav Petkov wrote:
> On Mon, Sep 12, 2016 at 10:05:36AM -0500, Tom Lendacky wrote:
>> I can look into that.  The reason I put this here is this is all the
>> early page fault support that is very specific to this file. I modified
>> an existing static function to take advantage of the mapping support.
> 
> Yeah, but all this code is SME-specific and doesn't belong there.
> AFAICT, it uses global/public symbols so there shouldn't be a problem to
> have it in mem_encrypt.c.

Ok, I'll look into moving this into mem_encrypt.c. I'd like to avoid
duplicating code so I may have to make that static function external
unless I find a better way.

Thanks,
Tom

> 
>> Hmmm, maybe... With the change to the early_memremap() the initrd is now
>> identified as BOOT_DATA in relocate_initrd() and so it will be mapped
>> and copied as non-encyrpted data. But since it was encrypted before the
>> call to relocate_initrd() it will copy encrypted bytes which will later
>> be accessed encrypted. That isn't clear though, so I'll rework
>> reserve_initrd() to perform the sme_early_mem_enc() once at the end
>> whether the initrd is re-located or not.
> 
> Makes sense.
>