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From: Matthew Garrett <mjg59@srcf.ucam.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: linux-kernel@vger.kernel.org,
	linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org
Subject: Re: [PATCH 07/11] kexec: Disable in a secure boot environment
Date: Tue, 4 Sep 2012 21:22:05 +0100	[thread overview]
Message-ID: <20120904202205.GA28903@srcf.ucam.org> (raw)
In-Reply-To: <87txvdzgur.fsf@xmission.com>

On Tue, Sep 04, 2012 at 01:13:32PM -0700, Eric W. Biederman wrote:
> 
> Matthew Garrett <mjg@redhat.com> writes:
> 
> > kexec could be used as a vector for a malicious user to use a signed kernel
> > to circumvent the secure boot trust model. In the long run we'll want to
> > support signed kexec payloads, but for the moment we should just disable
> > loading entirely in that situation.
> 
> Nacked-by: "Eric W. Biederman" <ebiederm@xmission.com>
> 
> This makes no sense.  The naming CAP_SECURE_FIRMWARE is attrocious,
> you aren't implementing or enforcing secure firmware.

I'm certainly not attached to the name, and have no problem replacing 
it.

> You don't give any justification for this other than to support some
> silly EFI feature.  Why would anyone want this if we were not booting
> under EFI?

Well, given that approximately everyone will be booting under EFI within 
18 months, treating it as a niche case seems a little short sighted. And 
secondly, there are already several non-EFI platforms that want to enact 
a policy preventing root from being able to arbitrarily replace the 
kernel. Given that people are doing this in the wild, it makes sense to 
move towards offering that policy in the mainline kernel.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

  reply	other threads:[~2012-09-04 20:22 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-04 15:55 [RFC] First attempt at kernel secure boot support Matthew Garrett
2012-09-04 15:55 ` [PATCH 01/11] Secure boot: Add new capability Matthew Garrett
2012-09-04 15:55 ` [PATCH 02/11] PCI: Lock down BAR access in secure boot environments Matthew Garrett
2012-10-01 21:00   ` Pavel Machek
2012-09-04 15:55 ` [PATCH 03/11] x86: Lock down IO port " Matthew Garrett
2012-09-04 16:16   ` Alan Cox
2012-09-04 16:16     ` Matthew Garrett
2012-09-04 15:55 ` [PATCH 04/11] ACPI: Limit access to custom_method Matthew Garrett
2012-09-04 15:55 ` [PATCH 05/11] asus-wmi: Restrict debugfs interface Matthew Garrett
2012-09-04 16:12   ` Alan Cox
2012-09-04 16:13     ` Matthew Garrett
2012-09-04 15:55 ` [PATCH 06/11] Restrict /dev/mem and /dev/kmem in secure boot setups Matthew Garrett
2012-09-04 15:55 ` [PATCH 07/11] kexec: Disable in a secure boot environment Matthew Garrett
2012-09-04 20:13   ` Eric W. Biederman
2012-09-04 20:22     ` Matthew Garrett [this message]
2012-09-04 21:13       ` Eric W. Biederman
2012-09-04 21:27         ` Matthew Garrett
2012-09-04 22:12           ` Eric W. Biederman
2012-09-04 23:25             ` Matthew Garrett
2012-09-05  4:33               ` Eric W. Biederman
2012-09-05  5:16                 ` Matthew Garrett
2012-09-05  7:00                   ` Eric W. Biederman
2012-09-05  7:03                     ` Matthew Garrett
2012-09-04 21:39         ` Alan Cox
2012-09-04 21:40           ` Matthew Garrett
2012-09-05 15:43             ` Roland Eggner
2012-09-05 15:46               ` Matthew Garrett
2012-09-05 21:13   ` Mimi Zohar
2012-09-05 21:41     ` Matthew Garrett
2012-09-05 21:49       ` Eric Paris
2012-09-04 15:55 ` [PATCH 08/11] Secure boot: Add a dummy kernel parameter that will switch on Secure Boot mode Matthew Garrett
2012-09-04 15:55 ` [PATCH 09/11] efi: Enable secure boot lockdown automatically when enabled in firmware Matthew Garrett
2012-09-04 15:55 ` [PATCH 10/11] acpi: Ignore acpi_rsdp kernel parameter in a secure boot environment Matthew Garrett
2012-09-04 16:30   ` Shuah Khan
2012-09-04 16:38     ` Matthew Garrett
2012-09-04 16:44       ` Shuah Khan
2012-09-04 20:37         ` Alan Cox
2012-09-04 20:37           ` Matthew Garrett
2012-09-04 20:50             ` Josh Boyer
2012-09-04 15:55 ` [PATCH 11/11] SELinux: define mapping for new Secure Boot capability Matthew Garrett
2012-09-04 16:08 ` [RFC] First attempt at kernel secure boot support Alan Cox
2012-09-04 16:12   ` Matthew Garrett
2012-10-01 21:07     ` Pavel Machek

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