On Wednesday, December 13, 2017 7:16:47 PM EST Kees Cook wrote:

> On Wed, Dec 13, 2017 at 3:58 PM, Steve Grubb <sgrubb@redhat.com> wrote:

> > Hello,

> >

> > Over the last month, the amount of seccomp events in audit logs is

> > sky-rocketing. I have over a million events in the last 2 days. Most of

> > this is generated by firefox and qt webkit.

> >

> > I am wondering if the audit package should ship a file for

> >

> > /usr/lib/sysctl.d/60-auditd.conf

> >

> > wherein it has

> >

> > kernel.seccomp.actions_logged = kill_process kill_thread errno

> >

> > Also, has anyone verified this sysctl is filtering audit events? Even with

> > the above, I have over a million events on a 4.14.3 kernel. Firefox alone

> > is generating over 50,000 events per hour.

>

> I don't think you'd want to log errno -- AIUI, that's used regularly

> by a lot of seccomp policy.

 

I'm not seeing any reporting errno. The ones reporting trap are coming in over 50,000 per hour. I don't think the filter is working.

 

[root@x2 ~]# cat /proc/sys/kernel/seccomp/actions_logged

kill_process kill_thread errno

[root@x2 ~]# date

Wed Dec 13 19:24:40 EST 2017

[root@x2 ~]# ausearch --start 19:24:40 -m seccomp --raw | aureport --event --summary -i

 

Event Summary Report

======================

total type

======================

170 SECCOMP

 

In the time it took to type the command 170 seccomp events were recorded from firefox.

 

[root@x2 ~]# ausearch --start 19:24:40 -m seccomp --just-one -i

----

node=x2 type=SECCOMP msg=audit(12/13/2017 19:24:56.454:199666) : auid=sgrubb uid=sgrubb gid=sgrubb ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=3394 comm=Web Content exe=/usr/lib64/firefox/firefox sig=SIG0 arch=x86_64 syscall=stat compat=0 ip=0x7f909c828635 code=trap

 

^^ trap. With the sheer amount of events being recorded, I think it's necessary to add a sysctl file to systems to suppress the logging. Especially when you consider that systemd-journal also gratuitously grabs audit logs and sends them to rsyslog.

 

-Steve