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From: Matthew Garrett <mjg59@google.com>
To: Matt Parnell <mparnell@gmail.com>
Cc: Kees Cook <keescook@chromium.org>,
	LSM List <linux-security-module@vger.kernel.org>,
	David Howells <dhowells@redhat.com>,
	matthew.garrett@nebula.com
Subject: Re: [PATCH] Kernel Lockdown: Add an option to allow raw MSR access even, in confidentiality mode.
Date: Mon, 2 Dec 2019 18:16:18 -0800	[thread overview]
Message-ID: <CACdnJuuDKX2GXZoubLGFoh8D3a1a38j+9rwu2iBZG6pqpqgokw@mail.gmail.com> (raw)
In-Reply-To: <62ccc074-ac6d-edea-10c6-925f99dfc592@gmail.com>

On Mon, Dec 2, 2019 at 6:01 PM Matt Parnell <mparnell@gmail.com> wrote:
>
> I should also mention the kernel itself thinks it is vulnerable with the
> MSRs locked down:
>
> [    7.367922] L1TF CPU bug present and SMT on, data leak possible. See
> CVE-2018-3646 and
> https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for
> details.

The lockdown code doesn't touch any of the codepaths the kernel uses
to access MSRs itself (a *lot* would break in that case), so if the
kernel is asserting this inappropriately then that seems like a kernel
bug.

  reply	other threads:[~2019-12-03  2:16 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-30  6:49 [PATCH] Kernel Lockdown: Add an option to allow raw MSR access even, in confidentiality mode Matt Parnell
2019-11-30 18:36 ` Kees Cook
2019-11-30 19:09   ` Matt Parnell
2019-12-01 20:53     ` Matt Parnell
2019-12-02 18:29       ` Matt Parnell
2019-12-02 22:55         ` Jordan Glover
2019-12-02 23:13           ` Matt Parnell
2019-12-02 23:29           ` Matthew Garrett
2019-12-02 23:31             ` Matt Parnell
2019-12-03  2:13   ` Matt Parnell
2019-12-03  2:16     ` Matthew Garrett [this message]
2019-12-03  2:24       ` Matt Parnell
2019-12-03  2:50         ` Matt Parnell
2019-12-03  3:57           ` Matt Parnell
2019-12-02 19:43 ` Matthew Garrett
2019-12-02 20:39   ` Matt Parnell

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