Re: [PATCH 10/10] LSM: Blob sharing support for S.A.R.A and LandLock

From: Kees Cook
Date: Thu Sep 13 2018 - 20:06:23 EST

On Thu, Sep 13, 2018 at 5:03 PM, Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
> On 9/13/2018 4:51 PM, Kees Cook wrote:
>> So, before we can really make a decision, I think we have to decide:
>> should ordering be arbitrary for even this level of stacking?
> Do we have a case where it matters? I know that I could write a
> module that would have issues if one hook got called and another
> didn't because because a precursor module hook failed. I don't
> think that any of the existing modules have this problem.

FWIW, I prefer having explicit ordering that cannot be changed at
runtime. I'm just concerned about painting ourselves (further) into a
corner with security= suddenly gaining ordering semantics, but maybe I
can just ignore this and we can point and laugh at anyone who gets
burned by some future change to making it order-sensitive. :)


Kees Cook
Pixel Security