Re: [PATCH v2 1/2] selinux: add tracepoint on denials

[Stephen Smalley]

On Fri, Aug 14, 2020 at 1:07 PM peter enderborg
<peter.enderborg@xxxxxxxx> wrote:
>
> On 8/14/20 6:51 PM, Stephen Smalley wrote:
> > On Fri, Aug 14, 2020 at 9:05 AM Thiébaud Weksteen <tweek@xxxxxxxxxx> wrote:
> >> On Thu, Aug 13, 2020 at 5:41 PM Stephen Smalley
> >> <stephen.smalley.work@xxxxxxxxx> wrote:
> >>> An explanation here of how one might go about decoding audited and
> >>> tclass would be helpful to users (even better would be a script to do it
> >>> for them).  Again, I know how to do that but not everyone using
> >>> perf/ftrace will.
> >> What about something along those lines:
> >>
> >> The tclass value can be mapped to a class by searching
> >> security/selinux/flask.h. The audited value is a bit field of the
> >> permissions described in security/selinux/av_permissions.h for the
> >> corresponding class.
> > Sure, I guess that works.  Would be nice if we just included the class
> > and permission name(s) in the event itself but I guess you viewed that
> > as too heavyweight?
>
> The class name is added in part 2. Im not sure how a proper format for permission
> would look like in trace terms. It is a list, right?

Yes.  See avc_audit_pre_callback() for example code to log the permission names.