Re: [PATCH RFC] perf_event: Add support for LSM and SELinux checks

[Joel Fernandes <joel@joelfernandes.org>]

On Wed, Oct 09, 2019 at 03:41:56PM -0700, Casey Schaufler wrote:
> On 10/9/2019 3:14 PM, James Morris wrote:
> > On Wed, 9 Oct 2019, Casey Schaufler wrote:
> >
> >> Please consider making the perf_alloc security blob maintained
> >> by the infrastructure rather than the individual modules. This
> >> will save it having to be changed later.
> > Is anyone planning on using this with full stacking?
> >
> > If not, we don't need the extra code & complexity. Stacking should only 
> > cover what's concretely required by in-tree users.
> 
> I don't believe it's any simpler for SELinux to do the allocation
> than for the infrastructure to do it. I don't see anyone's head
> exploding over the existing infrastructure allocation of blobs.
> We're likely to want it at some point, so why not avoid the hassle
> and delay by doing it the "new" way up front?
> 

I don't see how it can be maintained by the users (assuming you meant
infrastructure as perf_event subsystem). The blob contains a SID which as far
as I know, is specific to SELinux. Do you have an in-tree example of this?

Further, this is also exactly it is done for BPF objects which I used as a
reference.

thanks,

 - Joel