Re: Filtering out non-interactive users
On Friday, January 14, 2011 11:37:01 am PJB wrote:
I've recently been working on a number of systems that need to
fulfill
auditing requirements for things such as "failed program executions,"
"failed file/directory deletions" and such, and we have been attempting to
use auditd to fulfill these requirements. However we've been having
difficulty filtering out the 'noise' from non-interactive processes since
our requirements only need us to capture these events for real human
users.
In older versions of the audit code, we used the following type of system
call auditing rule which seemed to work pretty well:
-a exit,always -S creat -S open -S openat -S truncate -S ftruncate -F
success=0 -F auid!=-1
This rule looks correct except that if you have a 64 bit system, I would suggest a -F
arch=b32 between the '-a' and '-S' and then another copy of the rule for
the 64 bit
arch.
Filtering on an 'auid!=-1' seemed to do a very good job of
stripping out
system calls from daemon processes and such. However at some point I guess
this was changed because we no longer seem to be able to capture any
system calls at all when we have this filter defined on a rule.
That should work. I'd try listing the rules back out to see if something is getting
mis-translated going into the kernel.
Can someone point me to documentation/examples or help me out with
the
proper syntax for setting up rules that will exclude the background
processes? We are using auditd 1.7.4 now and the 'auid' filter above no
longer does the job.
There's been a lot of bugs fixed since then. You might try building a newer auditctl
and trying it out to see if that makes a difference. Also note that the event capturing
is done by the kernel and the kernel version would matter more than the auditd
version.
Are you getting other events like logins? Just making sure your disk isn't full or
something else. And when you do auditctl -s, it shows the audit system is enabled?
-Steve