On Monday, March 20, 2017 8:08:27 AM EDT Paul Moore wrote: > On Sun, Mar 19, 2017 at 9:46 PM, Steve Grubb <[email protected]> wrote: > > Hello Richard and Paul, > > > > I was going to do a blog write up about booting the system with > > audit_backlog_limit=8192 for STIG users and have stumbled on to a mystery. > > The kernel initializes the variable to 64 at power on. During boot, if > > audit == 1, then it holds events in the hopes that an audit daemon will > > show up later and drain all the events. Anything over 64 events should > > fall off the end and increment the lost counter and put a notice in > > syslog. > > > > However, when booting with audit_backlog_limit=8192, as soon as I log in I > > run "auditctl -s" I can see I've lost 73 events. The I run "aureport > > --start boot" and I see 644 total events. This is nowhere near the 8192 > > limit that I asked for. So, why am I losing events? > > > > Additionally, I checked the logs and there is absolutely no message in > > syslog showing that I've lost events. This is with failure mode set to 1 > > - which is default at power on. And this is in spite of the the fact that > > the source code seems to show that it should have printk'ed something. > > > > Any ideas? Can you replicate this finding? > > It's funny, I just noticed this for the first time on Friday (the > exact same lost count too), although it was a development kernel build > with a *heavily* modified audit subsystem so I just assumed I had > broken something with the queuing, the lost counter, or both. It's > possible I still may have broken something in the v4.10 queue rework, > or something broke a long time ago and we are just noticing it now. > > First off, can you create a GitHub issue for this
Lost events during boot #38. > and include your kernel build (e.g. 'uname -r')? # uname -r 4.9.13-101.fc24.x86_64 > Second, if you are seeing this on a +v4.10 kernel, do you see the same > results with a +v4.9 kernel? Yes, and I tried a 4.8.10 and see it there as well. I then checked a 3.10 RHEL 7 kernel and don't see any lost events and that even has a backlog_limit of the default of 64. I then found a system with a 4.5.5 kernel and it also was losing events. -Steve -- Linux-audit mailing list [email protected] https://www.redhat.com/mailman/listinfo/linux-audit
