Re: [PATCH ghak10 v5 1/2] audit: Add functions to log time adjustments

From: Ondrej Mosnacek
Date: Mon Aug 27 2018 - 05:13:32 EST

On Mon, Aug 27, 2018 at 9:50 AM Miroslav Lichvar <mlichvar@xxxxxxxxxx> 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]). 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.


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