Re: [PATCH 0/7 v22] LSM: Multiple concurrent LSMs

From: Kees Cook
Date: Fri May 08 2015 - 13:00:24 EST

On Fri, May 8, 2015 at 9:13 AM, Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
> On 5/8/2015 4:21 AM, Mimi Zohar wrote:
>> On Thu, 2015-05-07 at 13:36 -0700, Casey Schaufler wrote:
>>> On 5/7/2015 1:23 PM, Stephen Smalley wrote:
>>>> On 05/07/2015 04:22 PM, Mimi Zohar wrote:
>>>>> On Thu, 2015-05-07 at 14:07 -0400, Paul Moore wrote:
>>>>>> On Thu, May 7, 2015 at 10:47 AM, Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
>>>>>>> On 5/7/2015 4:37 AM, James Morris wrote:
>>>>>>>> On Sat, 2 May 2015, Casey Schaufler wrote:
>>>>>>>>> Subject: [PATCH 0/7 v22] LSM: Multiple concurrent LSMs
>>>>>>>> Please add all of the Acked-by etc. from the patch review process.
>>>>>>> For v21 I had Acks from:
>>>>>>> John Johansen <john.johansen@xxxxxxxxxxxxx>
>>>>>>> Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
>>>>>>> Stephen Smalley <sds@xxxxxxxxxxxxx> (after patch 8/7)
>>>>>>> Kees Cook <keescook@xxxxxxxxxxxx>
>>>>>>> Would you check out v22 and supply (or not) your Acks?
>>>>>>> Eric, Paul, it would be reassuring if you'd chime in as well.
>>>>>> Kubernetes has swallowed Eric whole I'm afraid, I don't think you want
>>>>>> to wait on him to review these patches.
>>>>>> However, it is a bit ridiculous that I haven't had time to seriously
>>>>>> review these patches yet; I promise to take a look and send my
>>>>>> comments/ACKs before my head hits the pillow tonight.
>>>>> Seems to be working with SELinux, EVM and IMA enabled. I haven't tried
>>>>> enabling an additional LSM. Casey, do you have an additional LSM for
>>>>> testing?
>>>> I've tested SELinux+Yama.
>>> The deepest "stack" you can have today is Capability+Yama+YourChoice.
>>> You always get Capability, so you really only get to choose if you stack
>>> Yama with something else. That's not more depth than you had before, but
>>> the special case coding for Capability and Yama is replaced to the general
>>> scheme.
>> Nice cleanup! I assume this will pave the way for other small, builtin
>> LSMs. :)
>> I'm now running with Yama as well. While enabling Yama, I noticed a
>> very minor issue with security/Kconfig. It permits defining Yama as the
>> default LSM when it is stacked.
> You don't get Yama called twice in that case, which would be
> the primary concern. I have maintained the existing behavior,
> I think. The Yama special case stacking will go away when the
> general LSM list specification mechanism ("yama,apparmor") comes
> in. That ought to be in the next round.

Yup, this all looks correct. Thanks!

Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>


Kees Cook
Chrome OS Security
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