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From: ebiederm@xmission.com (Eric W. Biederman)
To: Matthew Garrett <mjg59@srcf.ucam.org>
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, 04 Sep 2012 21:33:31 -0700	[thread overview]
Message-ID: <871uihozqc.fsf@xmission.com> (raw)
In-Reply-To: <20120904232503.GA1077@srcf.ucam.org> (Matthew Garrett's message of "Wed, 5 Sep 2012 00:25:03 +0100")

Matthew Garrett <mjg59@srcf.ucam.org> writes:

> On Tue, Sep 04, 2012 at 03:12:52PM -0700, Eric W. Biederman wrote:
>> Matthew Garrett <mjg59@srcf.ucam.org> writes:
>> > The driving force behind this code right now is that our choices are 
>> > either (1) do something like this, or (2) disable kexec entirely.
>> 
>> Actually there is an interesting question here. Why does even EFI secure
>> boot justify this?  If I install my own key in EFI I should be able to
>> boot a kernel that does anything I want it to.   My machine doing what I
>> want it to is the point of trusted boot is it not?
>
> The full implementation should trust keys that are trusted by the 
> platform, so it'd boot any kexec image you cared to sign. Or simply 
> patch this code out and rebuild and self-sign, or disable the code that 
> turns off the capability when in secure boot mode. I've no objection to 
> putting that behind an #ifdef.

I will be happy to see a version of kexec that accepts signed images,
allowing the functionality to work in your brave new world where
everything must be signed.

Until then I don't see a point in merging anything else.

I will be happy to see some reasonable patchs for signing support on the
kexec path.

Eric

  reply	other threads:[~2012-09-05  4:33 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
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 [this message]
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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