Re: [kernel-hardening] Re: [PATCH RFC v2 1/3] LSM: Allow per LSM module per "struct task_struct" blob.

From: Kees Cook
Date: Tue Apr 11 2017 - 15:58:07 EST


On Tue, Apr 11, 2017 at 12:54 PM, Casey Schaufler
<casey@xxxxxxxxxxxxxxxx> wrote:
> On 4/10/2017 9:43 PM, Kees Cook wrote:
>> On Mon, Apr 10, 2017 at 1:00 PM, Djalal Harouni <tixxdz@xxxxxxxxx> wrote:
>>> On Mon, Apr 10, 2017 at 9:26 PM, Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
>>>> I think that would be the prudent approach. There is still
>>>> the possibility that blob sharing (or full stacking, if you
>>>> prefer) won't be accepted any time soon.
>>> Ok Casey! I will wait for more feedback, and if other maintainers do
>>> not object, I will convert it back to rhashtables in next iterations
>>> making sure that it should be simple to convert later to a blob
>>> sharing mechanism.
>> Would it be possible just to add a single field to task_struct if this
>> LSM is built in? I feel like rhashtables is a huge overhead when a
>> single field is all that's needed.
>
> Special casing the task_struct based on which modules
> are compiled in would work, but I'm under the impression
> that there's a strong desire to keep to one pointer for
> security module information in the major structures.

Right, I meant as far as keeping this patch set unblocked by the other one...

-Kees

--
Kees Cook
Pixel Security