Messages in this thread | | | Date | Mon, 23 Sep 2019 17:00:21 -0400 | From | Richard Guy Briggs <> | Subject | Re: ntp audit spew. |
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On 2019-09-23 12:14, Paul Moore wrote: > On Mon, Sep 23, 2019 at 11:50 AM Dave Jones <davej@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
Odd. It appears these two above should have the same serial number and should be accompanied by a syscall record. It appears that it has no context to update to connect the two records. Is it possible it is not being called in a task context? If that were the case though, I'd expect audit_dummy_context() to return 1...
Checking audit_enabled should not be necessary but might fix the problem, but still not explain why we're getting these records.
> > [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'? 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). > > -- > paul moore > www.paul-moore.com > > -- > Linux-audit mailing list > Linux-audit@redhat.com > https://www.redhat.com/mailman/listinfo/linux-audit
- RGB
-- Richard Guy Briggs <rgb@redhat.com> 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
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