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From:   Ondrej Mosnacek <omosnace@redhat.com>
Date:   Thu, 13 Sep 2018 15:59:19 +0200
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Subject: Re: [PATCH ghak10 v5 1/2] audit: Add functions to log time adjustments
To:     Steve Grubb <sgrubb@redhat.com>
Cc:     Miroslav Lichvar <mlichvar@redhat.com>,
        Linux-Audit Mailing List <linux-audit@redhat.com>,
        Paul Moore <paul@paul-moore.com>,
        Richard Guy Briggs <rgb@redhat.com>,
        John Stultz <john.stultz@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Stephen Boyd <sboyd@kernel.org>,
        Linux kernel mailing list <linux-kernel@vger.kernel.org>
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On Mon, Aug 27, 2018 at 6:38 PM Steve Grubb <sgrubb@redhat.com> wrote:
> On Monday, August 27, 2018 5:13:17 AM EDT Ondrej Mosnacek wrote:
> > On Mon, Aug 27, 2018 at 9:50 AM Miroslav Lichvar <mlichvar@redhat.com>
> wrote:
> > > On Fri, Aug 24, 2018 at 02:00:00PM +0200, Ondrej Mosnacek wrote:
> > > > This patch adds two auxiliary record types that will be used to
> > > > annotate
> > > > the adjtimex SYSCALL records with the NTP/timekeeping values that have
> > > > been changed.
> > >
> > > It seems the "adjust" function intentionally logs also calls/modes
> > > that don't actually change anything. Can you please explain it a bit
> > > in the message?
> > >
> > > NTP/PTP daemons typically don't read the adjtimex values in a normal
> > > operation and overwrite them on each update, even if they don't
> > > change. If the audit function checked that oldval != newval, the
> > > number of messages would be reduced and it might be easier to follow.
> >
> > We actually want to log any attempt to change a value, as even an
> > intention to set/change something could be a hint that the process is
> > trying to do something bad (see discussion at [1]).
>
> One of the problems is that these applications can flood the logs very
> quickly. An attempt to change is not needed unless it fails for permissions
> reasons. So, limiting to actual changes is probably a good thing.

Well, Richard seemed to "violently" agree with the opposite, so now I
don't know which way to go... Paul, you are the official tie-breaker
here, which do you prefer?

>
> -Steve
>
> > There are valid
> > arguments both for and against this choice, but we have to pick one in
> > the end... Anyway, I should explain the reasoning in the commit
> > message better, right now it just states the fact without explanation
> > (in the second patch), thank you for pointing my attention to it.
> >
> > [1] https://www.redhat.com/archives/linux-audit/2018-July/msg00061.html
> >
> > --
> > Ondrej Mosnacek <omosnace at redhat dot com>
> > Associate Software Engineer, Security Technologies
> > Red Hat, Inc.
>
>
>
>

--
Ondrej Mosnacek <omosnace at redhat dot com>
Associate Software Engineer, Security Technologies
Red Hat, Inc.