Should audit_seccomp check audit_enabled?

[Paul Moore]

On October 23, 2015 5:30:45 PM Andy Lutomirski <luto at amacapital.net> wrote:

> On Fri, Oct 23, 2015 at 2:22 PM, Kees Cook <keescook at chromium.org> wrote:
>> On Fri, Oct 23, 2015 at 2:07 PM, Andy Lutomirski <luto at amacapital.net> wrote:
>>> On Oct 23, 2015 10:01 AM, "Kees Cook" <keescook at chromium.org> wrote:
>>>>
>>>> On Fri, Oct 23, 2015 at 9:19 AM, Andy Lutomirski <luto at amacapital.net> wrote:
>>>> > I would argue that, if auditing is off, audit_seccomp shouldn't do
>>>> > anything.  After all, unlike e.g. selinux, seccomp is not a systemwide
>>>> > policy, and seccomp signals might be ordinary behavior that's internal
>>>> > to the seccomp-using application.  IOW, for people with audit compiled
>>>> > in and subscribed by journald but switched off, I think that the
>>>> > records shouldn't be emitted.
>>>> >
>>>> > If you agree, I can send the two-line patch.
>>>>
>>>> I think signr==0 states (which I would identify as "intended
>>>> behavior") don't need to be reported under any situation, but audit
>>>> folks wanted to keep it around.
>>>
>>> Even if there is a nonzero signr, it could just be a program opting to
>>> trap and emulate one of its own syscalls.
>>
>> At present, that is a rare situation. Programs tend to be ptrace
>> managed externally. Is there anything catching SIGSYS itself?
>>
>
> I wrote one once.  I also wrote a whole set of patches for libseccomp
> to make it easier that never went anywhere -- I should dust those off
> and package them into their own library.

It has been a while since we discussed those patches, but if I remember 
correctly it was going to be very difficult to do it in an arch agnostic 
way and that was a concern.

--
paul moore
www.paul-moore.com