Message-ID: <554156A1.3010903@kernel.org>
Date: Wed, 29 Apr 2015 15:09:37 -0700
From: Andy Lutomirski <luto@kernel.org>
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To: Shawn Chang <citypw@gmail.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
CC: spender@grsecurity.net, keescook@chromium.org
Subject: Re: [PATCH] Hardening memory maunipulation.
References: <1430321975-13626-1-git-send-email-citypw@gmail.com>
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On 04/29/2015 08:39 AM, Shawn Chang wrote:
> From: Shawn C <citypw@gmail.com>
>
> Hi kernel maintainers,
>
> It won't allow the address above the TASK_SIZE being mmap'ed( or mprotect'ed).
> This patch is from PaX/Grsecurity.
>
> Thanks for your review time!

Does this actually reduce the attack surface of anything?

These functions all search for vmas.  If there's a vma outside of the 
user range, we have a problem.

Also, that use of TASK_SIZE is IMO ridiculous.  Shouldn't be TASK_SIZE_MAX?

--Andy, who is annoyed every time another pointless TIF_IA32 reference, 
even hidden in a macro, makes it into the kernel
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