Re: [PATCH 00/12] One more attempt at useful kernel lockdown

Josh Boyer
2013-09-09T20:13:59Z

On Mon, Sep 9, 2013 at 4:10 PM, David Lang <david@lang.hm> wrote:
> On Mon, 9 Sep 2013, Josh Boyer wrote:
>
>> On Mon, Sep 9, 2013 at 3:41 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>>>
>>> On 09/09/2013 12:01 PM, Valdis.Kletnieks@vt.edu wrote:
>>>>
>>>> On Mon, 09 Sep 2013 11:25:38 -0700, David Lang said:
>>>>
>>>>> Given that we know that people want signed binaries without
>>>>> blocking kexec, you should have '1' just enforce module signing
>>>>> and '2' (or higher) implement a full lockdown including kexec.
>>>>
>>>>
>>>>> Or, eliminate the -1 permanently insecure option and make this a
>>>>> bitmask, if someone wants to enable every possible lockdown, have
>>>>> them set it to "all 1's", define the bits only as you need them.
>>>>
>>>>
>>>> This strikes me as much more workable than one big sledgehammer.
>>>>
>>>
>>> I.e. capabilities ;)
>>
>>
>> Circles. All I see here are circles.
>
>
> the thing is that these are not circles. they are separate orthoginal things
> that you may or may not want to allow.
>
> If this was a simple set of circles, then this could be defined as a vector
> instead of bitmap, the further you go the more secure you are.

I didn't mean your recommendation of using a bitmask. I understood
your proposal and I don't even disagree with it really. I was
replying to something else.

josh