linux-kernel - Re: [PATCH v3 0/6] kernel ASLR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAGXu5jJ0ZQqphMkzEGt4tDL-F9Y47pCftFJGB4f3buFmJ6h8ZA@mail.gmail.com>
Date:	Fri, 26 Apr 2013 11:53:28 -0700
From:	Kees Cook <keescook@...omium.org>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	"kernel-hardening@...ts.openwall.com" 
	<kernel-hardening@...ts.openwall.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"x86@...nel.org" <x86@...nel.org>,
	Jarkko Sakkinen <jarkko.sakkinen@...el.com>,
	Matthew Garrett <mjg@...hat.com>,
	Matt Fleming <matt.fleming@...el.com>,
	Eric Northup <digitaleric@...gle.com>,
	Dan Rosenberg <drosenberg@...curity.com>,
	Julien Tinnes <jln@...gle.com>, Will Drewry <wad@...omium.org>
Subject: Re: [PATCH v3 0/6] kernel ASLR

On Thu, Apr 25, 2013 at 3:01 PM, H. Peter Anvin <hpa@...or.com> wrote:
> On 04/25/2013 02:54 PM, Kees Cook wrote:
>> This continues to build on the tip/kaslr patches for KASLR. This series
>> converts the logic to C, and moves both relocation and address selection
>> into the decompress_kernel path. Several areas were refactored to allow
>> for some code reuse (e.g. CPU flags, kernel command line).
>>
>> This does not yet attempt to rework the page tables to handle an arbitrary
>> physical memory location on x86_64. I would love some suggestions on
>> how to do this. :)
>>
>
> We *should* already support arbitrary physical memory locations at least
> in the kernel proper (the decompressor might need some work.)
>
> We may want to do in the decompressor what we already do in the kernel,
> and set up a #PF handler which creates page tables on demand.  That way
> you can simply treat the entire memory space as a single linear space.

I'll need to compare the logic used for that against what's in
head_64.S for setting up the initial tables. And mapping the kernel
chunk as not 1-to-1, etc.

In the meantime, I'll send a v4 series with the other identified
changes since everything else (up to the 64-bit phy/virt detachment)
seems to be working.

-Kees

--
Kees Cook
Chrome OS Security
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/