Re: ntp audit spew.
On Monday, September 23, 2019 12:14:14 PM EDT Paul Moore wrote:
On Mon, Sep 23, 2019 at 11:50 AM Dave Jones
<davej(a)codemonkey.org.uk>
wrote:
> I have some hosts that are constantly spewing audit messages
like so:
>
> [46897.591182] audit: type=1333 audit(1569250288.663:220): op=offset
> old=2543677901372 new=2980866217213 [46897.591184] audit: type=1333
> audit(1569250288.663:221): op=freq old=-2443166611284 new=-2436281764244
> [48850.604005] audit: type=1333 audit(1569252241.675:222): op=offset
> old=1850302393317 new=3190241577926 [48850.604008] audit: type=1333
> audit(1569252241.675:223): op=freq old=-2436281764244 new=-2413071187316
> [49926.567270] audit: type=1333 audit(1569253317.638:224): op=offset
> old=2453141035832 new=2372389610455 [49926.567273] audit: type=1333
> audit(1569253317.638:225): op=freq old=-2413071187316 new=-2403561671476
>
> This gets emitted every time ntp makes an adjustment, which is apparently
> very frequent on some hosts.
>
>
> Audit isn't even enabled on these machines.
>
> # auditctl -l
> No rules
[NOTE: added linux-audit to the CC line]
There is an audit mailing list, please CC it when you have audit
concerns/questions/etc.
What happens when you run 'auditctl -a never,task'?
Actually, "-e 0" should turn it off. There is a general problem where systemd
turns on auditing just because it can. The above rule just makes audit
processes inauditable, but does not affect the kernel originating events.
-Steve
That *should*
silence those messages as the audit_ntp_log() function has the
requisite audit_dummy_context() check. FWIW, this is the distro
default for many (most? all?) distros; for example, check
/etc/audit/audit.rules on a stock Fedora system. A more selective
configuration could simply exclude the TIME_ADJNTPVAL record (type
1333) from the records that the kernel emits.
We could also add a audit_enabled check at the top of
audit_ntp_log()/__audit_ntp_log(), but I imagine some of that depends
on the various security requirements (they can be bizzare and I can't
say I'm up to date on all those - Steve Grubb should be able to
comment on that).