Re: [PATCH ghak111 V1] audit: deliver siginfo regarless of syscall

From: Richard Guy Briggs
Date: Tue Apr 09 2019 - 11:57:41 EST


On 2019-04-09 17:37, Steve Grubb wrote:
> On Tue, 9 Apr 2019 10:02:59 -0400
> Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
>
> > On 2019-04-09 08:01, Steve Grubb wrote:
> > > On Mon, 8 Apr 2019 23:52:29 -0400 Richard Guy Briggs
> > > <rgb@xxxxxxxxxx> wrote:
> > > > When a process signals the audit daemon (shutdown, rotate, resume,
> > > > reconfig) but syscall auditing is not enabled, we still want to
> > > > know the identity of the process sending the signal to the audit
> > > > daemon.
> > >
> > > Why? If syscall auditing is disabled, then there is no requirement
> > > to provide anything. What is the real problem that you are seeing?
> >
> > Shutdown messages with -1 in them rather than the real values.
>
> OK. We can fix that by patching auditd to see if auditing is enabled
> before requesting signal info. If auditing is disabled, the proper
> action is for the kernel to ignore any audit userspace messages except
> the configuration commands.

If auditing is disabled in the kernel, none of this is trackable. It is
for those as yet unsupported arches that can run audit enabled but
without auditsyscall support.

Here's a current sample with CONFIG_AUDIT and ~CONFIG_AUDITSYSCALL
configured, note "auid=" and "pid=":

killall -HUP auditd
type=DAEMON_CONFIG msg=audit(2019-04-09 11:37:04.508:3266) op=reconfigure state=changed auid=unset pid=-1 subj=? res=success

killall -TERM auditd
type=DAEMON_END msg=audit(2019-04-09 11:51:50.441:5709) : op=terminate auid=unset pid=-1 subj=? res=success

and the same with the patch applied:

killall -HUP auditd
type=DAEMON_CONFIG msg=audit(2019-04-09 11:42:40.851:8924) op=reconfigure state=changed auid=root pid=652 subj=? res=success

killall -TERM auditd
type=DAEMON_END msg=audit(2019-04-09 11:51:50.441:5709) : op=terminate auid=root pid=652 subj=? res=success

The USR1 "rotate" and USR2 "resume" log messages need to be fixed in
userspace.

> -Steve

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635