Re: ntp audit spew.

From: Eric Paris
Date: Mon Sep 23 2019 - 15:49:56 EST


Is this the thing where systemd is listening on the multicast netlink
socket and causes everything to come out kmesg as well?

On Mon, 2019-09-23 at 15:49 -0400, Dave Jones wrote:
> On Mon, Sep 23, 2019 at 02:57:08PM -0400, Paul Moore wrote:
> > On Mon, Sep 23, 2019 at 12:58 PM Dave Jones <
> davej@xxxxxxxxxxxxxxxxx> wrote:
> > > On Mon, Sep 23, 2019 at 12:14:14PM -0400, Paul Moore wrote:
> > > > On Mon, Sep 23, 2019 at 11:50 AM Dave Jones <
> davej@xxxxxxxxxxxxxxxxx> 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
> > > >
> > > > 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.
> > >
> > > They still get emitted.
> > >
> > > > FWIW, this is the distro
> > > > default for many (most? all?) distros; for example, check
> > > > /etc/audit/audit.rules on a stock Fedora system.
> > >
> > > As these machines aren't using audit, they aren't running auditd
> either.
> > > Essentially: nothing enables audit, but the kernel side
> continues to log
> > > ntp regardless (no other audit messages seem to do this).
> >
> > What does your kernel command line look like? Do you have
> "audit=1"
> > somewhere in there?
>
> nope.
>
> ro root=LABEL=/ biosdevname=0 net.ifnames=0 fsck.repair=yes
> systemd.gpt_auto=0 pcie_pme=nomsi ipv6.autoconf=0 erst_disable
> crashkernel=128M console=tty0 console=ttyS1,57600
> intel_iommu=tboot_noforce
>
> Dave
>