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

On 2018-09-13 15:59, Ondrej Mosnacek wrote: > On Mon, Aug 27, 2018 at 6:38 PM Steve Grubb <sgrubb(a)redhat.com&gt; 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(a)redhat.com&gt; > > 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? The circumstances have changed with new information being added. I recall violently agreeing several iterations ago with your previous assessment, which has also changed with this new information. I'd agree with Steve that a flood of information about something that did not change value could hide important information.

(BTW: The expression "to violoently agree with" is generally used in a situation where two parties appear to have been arguing two different sides of an issue and then realize they have much more in common than initially apparent.)

> > -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> > > Ondrej Mosnacek <omosnace at redhat dot com> - RGB -- Richard Guy Briggs <rgb(a)redhat.com&gt; 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