[PATCH 5/7] efi: Get the secure boot status [ver #3]
David Howells
dhowells at redhat.com
Fri Nov 25 04:35:03 PST 2016
Ard Biesheuvel <ard.biesheuvel at linaro.org> wrote:
> Yes. In pre-2.6, DeployedMode is not a reserved name, and so it may be
> possible for someone to slip in a DeployedMode=0 on a secure boot
> enabled system to trick the kernel into thinking lockdown should be
> disabled.
How does one get the version number? Unfortunately, searching the document
for 'version' doesn't help as every page has that in the footer:-/
> > + if (val == 1)
> > + return 0;
>
> I think the logic is the wrong way around here. Secure Boot is enabled
> if SecureBoot=1 and SetupMode=0, unless DeployedMode=0. So you should
> return 0 here if val == 0, but only when running on 2.6 or later.
Good point.
David
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