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Date: Tue, 9 Apr 2013 11:53:02 -0700
Message-ID: <CAGXu5j+_sSVsB-D+zYyzBkj0HKzyVfJOBRAxMRmge2t=sSrTAg@mail.gmail.com>
Subject: Re: [kernel-hardening] Re: [PATCH] x86: make IDT read-only
From: Kees Cook <keescook@chromium.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "kernel-hardening@lists.openwall.com" 
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On Tue, Apr 9, 2013 at 11:50 AM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 04/09/2013 11:46 AM, Kees Cook wrote:
>>
>> Ah-ha! Yes, I see now when comparing the debug/kernel_page_tables
>> reports. It's just the High Kernel Mapping that we care about.
>> Addresses outside that range are less of a leak. Excellent, then GDT
>> may not be a problem. Whew.
>>
>
> It does beg the question if we need to randomize kmalloc... which could
> have issues by itself.

Agreed, but this should be a separate issue. As is the fact that GDT
is writable and a discoverable target.

-Kees

--
Kees Cook
Chrome OS Security
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