Re: [PATCH v2] x86, kaslr: propagate base load address calculation

From: Kees Cook
Date: Mon Feb 16 2015 - 14:27:49 EST

On Mon, Feb 16, 2015 at 3:55 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
> On Fri, Feb 13, 2015 at 03:25:26PM -0800, Kees Cook wrote:
>> No, no; I agree: a malicious boot loader is a lost cause. I mean
>> mostly from a misbehavior perspective. Like, someone sees "kaslr" in
>> the setup args and thinks they can set it to 1 and boot a kernel, etc.
>> Or they set it to 0, but they lack HIBERNATION and "1" gets appended,
>> but the setup_data parser sees the boot-loader one set to 0, etc. I'm
>> just curious if we should avoid getting some poor system into a
>> confusing state.
> Well, we can apply the rule of the last setting sticks and since the
> kernel is always going to be adding the last setup_data element of
> type SETUP_KASLR (the boot loader ones will be somewhere on the list
> in-between and we add to the end), we're fine, no?

Sounds good to me!


> --
> Regards/Gruss,
> Boris.
> ECO tip #101: Trim your mails when you reply.
> --

Kees Cook
Chrome OS Security
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