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Date: Fri, 13 Dec 2013 09:20:45 +0100
From: Vegard Nossum <vegard.nossum@oracle.com>
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To: "Theodore Ts'o" <tytso@mit.edu>, linux-kernel@vger.kernel.org,
        Tommi Rantala <tt.rantala@gmail.com>, Ingo Molnar <mingo@kernel.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Andy Lutomirski <luto@amacapital.net>,
        Kees Cook <keescook@chromium.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Alan Cox <alan@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jason Wang <jasowang@redhat.com>,
        "David S. Miller" <davem@davemloft.net>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        James Morris <james.l.morris@oracle.com>
Subject: Re: [PATCH 1/9] Known exploit detection
References: <1386867152-24072-1-git-send-email-vegard.nossum@oracle.com> <20131212190659.GG13547@thunk.org>
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On 12/12/2013 08:06 PM, Theodore Ts'o wrote:
> On Thu, Dec 12, 2013 at 05:52:24PM +0100, vegard.nossum@oracle.com wrote:
>> The idea is simple -- since different kernel versions are vulnerable to
>> different root exploits, hackers most likely try multiple exploits before
>> they actually succeed.
>
> Suppose we put put this into the mainstream kernel.  Wouldn't writers
> of root kit adapt by checking for the kernel version to avoid checking
> for exploits that are known not work?  So the question is whether the
> additional complexity in the kernel is going to be worth it, since
> once the attackers adapt, the benefits of trying to detect attacks for
> mitigated exploits will be minimal.

Yeah, you could probably avoid detection by being more careful. But I 
think it would be worth making it harder; I'd argue that the "additional 
complexity" in this case is minimal, since we are mostly talking about 
~1 line added to an error path for each critical vulnerability.


Vegard