Stuff I found in my log?

[Paul Howarth]

On Tue, 2006-05-23 at 17:12 -0700, Knute Johnson wrote:
> I found some interesting things in my 'messages' log today.  I'm not 
> sure what they mean and would appreciate any information.
> 
> This one is the most bothersome.  It appears that 'useradd' was 
> prevented from running this morning only I didn't run it.  Would any 
> other programs run 'useradd' and what would cause it to be denied?
> 
> May 23 05:11:49 rabbitbrush kernel: audit(1148386309.877:556): avc:  
> denied  { write } for  pid=13906 comm="useradd" name="[1708464]" 
> dev=pipefs ino=1708464 scontext=user_u:system_r:useradd_t:s0 
> tcontext=user_u:system_r:unconfined_t:s0 tclass=fifo_file

useradd is often run in the pre-install scripts of rpm packages when the
package provides something that runs as a service. You probably updated
such a package (or yum did it automatically in the overnight run). For
instance, I got one of these when avahi was updated recently. The
pre-install script for the avahi package is:

# Add the "avahi" user
/usr/sbin/useradd -c 'Avahi daemon' -u 70 \
        -s /sbin/nologin -r -d '/' avahi 2> /dev/null || :

The denial is coming because useradd is trying to write its output to a
pipe, which is not allowed by policy. Perhaps it should be?

Anyway, I think this one's harmless.

> There are a boatload of these messages.  I know that 'webalizer' is a 
> statistics formatter for the web server but why would it be run 
> dozens of times and be denied?
> 
> May 23 04:02:02 rabbitbrush kernel: audit(1148382121.861:514): avc:  
> denied  { create } for  pid=12313 comm="webalizer" 
> scontext=user_u:system_r:webalizer_t:s0 
> tcontext=user_u:system_r:webalizer_t:s0 tclass=netlink_route_socket

I get these too. I asked about it yesterday but no response yet. Looking
at the policy for other packages, and bearing in mind that webalizer
still seems to work despite the denials, I suspect that these can be
dontaudit-ed, but I'd like to know what they are first.

Paul.