Re: Should audit_seccomp check audit_enabled?

From: Kees Cook
Date: Fri Oct 23 2015 - 17:22:54 EST


On Fri, Oct 23, 2015 at 2:07 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> On Oct 23, 2015 10:01 AM, "Kees Cook" <keescook@xxxxxxxxxxxx> wrote:
>>
>> On Fri, Oct 23, 2015 at 9:19 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> 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?

-Kees

--
Kees Cook
Chrome OS Security
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