Re: [Ksummit-discuss] [TECH TOPIC] Kernel Hardening

[Shuah Khan <shuahkh@osg.samsung.com>]

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On 08/25/2015 10:30 AM, Mark Brown wrote:
> On Tue, Aug 25, 2015 at 09:15:32AM -0600, Shuah Khan wrote:
>> On Mon, Aug 24, 2015 at 10:35 AM, Kees Cook
>> <keescook@chromium.org> wrote:
> 
>>> I agree with the sentiment here, but not with the language.
>>> Finding flaws (which is what selftests, KASan, Trinity, etc do)
>>> isn't hardening. Hardening is stopping the exploitation of
>>> flaws. The hardening the kernel needs is about taking away
>>> exploitation tools, not killing bugs. (Though killing bugs is
>>> still great.)
> 
>> I agree with Kees on this. Kselftest or any other test suites can
>> help with regression testing and make sure Kernel works the way
>> it should. Also these tests can tell us if kernel is hardened or
>> not.
> 
>> Hardening means something different to me. i.e making sure
>> kernel can protect against attacks and fail gracefully. This is
>> something to address during design and development process.
> 
> Testsuites can help here if we get into the habit of making sure
> they exercise error conditions; they're off to the side a bit but
> they can be a useful way of promoting good practice (at least in my
> experience).
> 

Yes. I agree. We can expand the Kselftest suite to do error checking,
maybe error injection. There are several tests now that are focused
on error checking and make sure syscalls fail correctly when used
incorrectly etc.

We could look into enhancing existing tests and add new tests as needed
to focus on finding kernel hardening related bugs and continue use them
for regression testing.

thanks,
- -- Shuah

- -- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978
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