Early processes (daemons) do not report audit events

Richard Guy Briggs rgb at redhat.com
Fri Sep 11 09:50:27 UTC 2015


On 15/09/10, Kangkook Jee wrote:
> Hi all,
> 
> I debugged a bit further to identify distributions that are affected by the issue.
> I repeated the same experiment with sshd from 3 more distributions.
> 
> CentOS Linux release 7.1.1503 (64-bit, 3.10.0-229.el7.x86_64): Problem NOT reproduced
> CentOS release 6.6 (64-bit, 2.6.32-504.el6.x86_64): Problem NOT reproduced
> Ubuntu 12.04.5 LTS (64-bit, 3.13.0-32-generic): Problem reproduced

For each of these examples, what is the value of the kernel command line
"audit=<value>" if it is even present?  It is possible that the CentOS
examples include "audit=1" while Ubuntu omits the line.  "cat
/proc/cmdline" should tell you the answer.

> After all, Ubuntu family are affected by the issue and I could confirm
> that results are inconsistent across two different distribution
> families. 

I would be curious what your results are with a recent Debian and with a
recent Fedora.

> If you can let us know how can we workaround the issue, it will be a great help.
> 
> Regards, Kangkook
> 
> 
> > On Sep 9, 2015, at 11:50 PM, Kangkook Jee <aixer77 at gmail.com> wrote:
> > 
> > Dear all,
> > 
> > We are developing custom user space audit agent to gather system wide system
> > call trace. While experimenting with various programs, we found out that
> > processes (daemons) that started early (along with the system bootstrapping) do
> > not report any audit events at all. These processes typically fall into PID
> > range of less than 2000. Here’s how I reproduced the symptom with sshd daemon.
> > 
> > 1. Reboot the system
> > 
> > 2. Add and enable audit events
> >    # /sbin/auditctl -a exit,always -F arch=b64 -S clone -S close -S creat -S dup
> >           -S dup2 -S dup3 -S execve -S exit -S exit_group -S fork -S open -S openat 
> >           -S unlink -S unlinkat -S vfork -S 288 -S accept -S bind -S connect 
> >           -S listen -S socket -S socketpair
> >    # /sbin/auditctl -e1 -b 102400
> > 
> > 3. Connect to the system via ssh
> >     Audit messages generated only from child processes and none are seen from
> >     the original daemon.
> > 
> > 4. Restart sshd 
> >     # restart ssh
> > 
> > 5. Connect again to the system via ssh
> >    Now, we see audit messages from both parent and child processes.
> > 
> > I did the experiment from Ubuntu 14.04.2 LTS distribution (64-bit, kernel
> > version 3.13.0-58-generic).
> > 
> > I first wonder whether this is intended behavior of audit framework or
> > not. If it is intended, I also want to know how can we configure auditd
> > differently to capture system calls from all processes. 
> > 
> > Thanks a lot for your help in advance!
> > 
> > Regards, Kangkook
> > 
> 

> --
> Linux-audit mailing list
> Linux-audit at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-audit


- RGB

--
Richard Guy Briggs <rbriggs at redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545




More information about the Linux-audit mailing list