Re: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes
On Thu, Aug 19, 2021 at 6:41 PM Casey Schaufler <casey(a)schaufler-ca.com> wrote:
On 8/18/2021 5:56 PM, Casey Schaufler wrote:
> On 8/18/2021 5:47 PM, Paul Moore wrote:
>> ...
>> I just spent a few minutes tracing the code paths up from audit
>> through netlink and then through the socket layer and I'm not seeing
>> anything obvious where the path differs from any other syscall;
>> current->audit_context *should* be valid just like any other syscall.
>> However, I do have to ask, are you only seeing these audit records
>> with a current->audit_context equal to NULL during early boot?
>
> Nope. Sorry.
It looks as if all of the NULL audit_context cases are for either
auditd or systemd. Given what the events are, this isn't especially
surprising.
I think we may be back to the "early boot" theory.
Unless you explicitly enable audit on the kernel cmdline, e.g.
"audit=1", processes started before userspace enables audit will not
have a properly allocated audit_context; see the "if
(likely(!audit_ever_enabled))" check at the top of audit_alloc() for
the reason why.
I could be wrong here, but I suspect if you add "audit=1" to your
kernel command line those remaining cases of NULL audit_contexts will
resolve themselves. If not, we still have work to do ... well, I mean
we still have (different) work to do even if this solves the mystery,
it's just that we can now explain what you are seeing :)
--
paul moore
www.paul-moore.com