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Date:   Thu, 9 Jan 2020 05:58:29 +1100 (AEDT)
From:   James Morris <jmorris@namei.org>
To:     Stephen Smalley <sds@tycho.nsa.gov>
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Subject: Re: [PATCH bpf-next v1 00/13] MAC and Audit policy using eBPF
 (KRSI)
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On Wed, 8 Jan 2020, Stephen Smalley wrote:

> This appears to impose a very different standard to this eBPF-based LSM than
> has been applied to the existing LSMs, e.g. we are required to preserve
> SELinux policy compatibility all the way back to Linux 2.6.0 such that new
> kernel with old policy does not break userspace.  If that standard isn't being
> applied to the eBPF-based LSM, it seems to inhibit its use in major Linux
> distros, since otherwise users will in fact start experiencing breakage on the
> first such incompatible change.  Not arguing for or against, just trying to
> make sure I understand correctly...

A different standard would be applied here vs. a standard LSM like 
SELinux, which are retrofitted access control systems.

I see KRSI as being more of a debugging / analytical API, rather than an 
access control system. You could of course build such a system with KRSI 
but it would need to provide a layer of abstraction for general purpose 
users.

So yes this would be a special case, as its real value is in being a 
special case, i.e. dynamic security telemetry.


-- 
James Morris
<jmorris@namei.org>