linux-kernel - Re: [PATCH v6 23/34] x86, realmode: Decrypt trampoline area if memory encryption is active

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>] [day] [month] [year] [list]

Message-ID: <20170614163903.fvlvscewnuk2u75x@pd.tnic>
Date:   Wed, 14 Jun 2017 18:39:04 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Tom Lendacky <thomas.lendacky@....com>
Cc:     linux-arch@...r.kernel.org, linux-efi@...r.kernel.org,
        kvm@...r.kernel.org, linux-doc@...r.kernel.org, x86@...nel.org,
        kexec@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kasan-dev@...glegroups.com, linux-mm@...ck.org,
        iommu@...ts.linux-foundation.org, Rik van Riel <riel@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Toshimitsu Kani <toshi.kani@....com>,
        Arnd Bergmann <arnd@...db.de>,
        Jonathan Corbet <corbet@....net>,
        Matt Fleming <matt@...eblueprint.co.uk>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Joerg Roedel <joro@...tes.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Larry Woodman <lwoodman@...hat.com>,
        Brijesh Singh <brijesh.singh@....com>,
        Ingo Molnar <mingo@...hat.com>,
        Andy Lutomirski <luto@...nel.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Alexander Potapenko <glider@...gle.com>,
        Dave Young <dyoung@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Dmitry Vyukov <dvyukov@...gle.com>
Subject: Re: [PATCH v6 23/34] x86, realmode: Decrypt trampoline area if
 memory encryption is active

On Wed, Jun 14, 2017 at 06:24:16PM +0200, Borislav Petkov wrote:
> On Wed, Jun 07, 2017 at 02:17:09PM -0500, Tom Lendacky wrote:
> > When Secure Memory Encryption is enabled, the trampoline area must not
> > be encrypted. A CPU running in real mode will not be able to decrypt
> > memory that has been encrypted because it will not be able to use addresses
> > with the memory encryption mask.
> > 
> > A recent change that added a new system_state value exposed a warning
> > issued by early_ioreamp() when the system_state was not SYSTEM_BOOTING.
> > At the stage where the trampoline area is decrypted, the system_state is
> > now SYSTEM_SCHEDULING. The check was changed to issue a warning if the
> > system_state is greater than or equal to SYSTEM_RUNNING.
> 
> This piece along with the hunk touching system_state absolutely needs to
> be a separate patch as it is unrelated.

Btw, pls send this now and separate from the patchset as it is a bugfix
that should go into sched/core.

Thanks.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.