cron issues with bash source (UNCLASSIFIED)
Jeremy Young
jrm16020 at gmail.com
Thu Aug 14 17:17:38 UTC 2014
Can you share the script, assuming that it's not classified? It may help
provide some context for the su question.
You can get some of your noise to go away by relabeling your syslog port:
semanage port -a -t syslogd_port_t -p tcp 601
A lot of the denials in your log are don't audited by default, but none of
them seem related to sourcing your functions file.
Finally, are the functions shared between scripts? If you include the
pertinent functions in the puppet-state script, do you continue to have
issues?
On Thu, Aug 14, 2014 at 9:27 AM, Shaw, Ray V CTR USARMY ARL (US) <
ray.v.shaw.ctr at mail.mil> wrote:
> Classification: UNCLASSIFIED
> Caveats: NONE
>
> Attached. I did notice some cron + bash related messages, so hopefully the
> answer is in there. They seemed to refer to our su wrapper, which I admit
> could be the problem, if cron is calling su in some way. I believe it's
> needed for some form of 2-factor authentication when using su. It was
> previously labeled as unconfined; yesterday I changed the labeling to match
> that of the su binary in the original RHEL6 coreutils package, but that
> didn't
> seem to help. I also tried reinstalling coreutils and using the standard
> su
> binary, but that didn't help either (I just get the same messages for "su"
> instead of "su.real").
>
> bash-4.1# ls -lZ /bin/su*
> lrwxrwxrwx. root root unconfined_u:object_r:bin_t:s0 /bin/su ->
> /bin/su.wrapper
> -r-xr-xr-x. root root system_u:object_r:su_exec_t:s0 /bin/su.real
> -r-sr-xr-x. root root system_u:object_r:su_exec_t:s0 /bin/su.wrapper
>
> The attached file shows the commands run both with and without dontaudit
> disabled:
>
> 10:12:30 runcon -u system_u -r system_r -t system_cronjob_t
> /etc/cron.daily/puppet-state
> 10:14:25 semodule -B
> 10:15:06 runcon -u system_u -r system_r -t system_cronjob_t
> /etc/cron.daily/puppet-state
> 10:15:16 ausearch -m avc -ts recent &> /root/avc3.txt
>
> --
> Ray Shaw (Contractor, STG)
> Army Research Laboratory
> CIO, Unix Support
>
>
> > -----Original Message-----
> > From: Jeremy Young [mailto:jrm16020 at gmail.com]
> > Sent: Thursday, August 14, 2014 9:43 AM
> > To: Shaw, Ray V CTR USARMY ARL (US)
> > Cc: selinux at lists.fedoraproject.org
> > Subject: Re: cron issues with bash source (UNCLASSIFIED)
> >
> > There are a few ways that you could speed up your troubleshooting:
> >
> > 1. Schedule your job with a file in /etc/cron.d to run the script in
> > /etc/cron.daily on a much more frequent interval 2. Use runcon to run
> > your script with the same context that crond would have when executing.
> > For example:
> > runcon -u system_u -r system_r -t system_cronjob_t
> > /etc/cron.daily/logrotate
> >
> > After you run the scripts (or at the end of the scripts), can you run
> > this and provide the raw audit messages?
> > ausearch -m avc -ts recent
> >
> >
> > On Thu, Aug 14, 2014 at 8:17 AM, Shaw, Ray V CTR USARMY ARL (US)
> > <ray.v.shaw.ctr at mail.mil> wrote:
> >
> >
> > Classification: UNCLASSIFIED
> > Caveats: NONE
> >
> > Background info: running RHEL6 with the latest updates, so
> > selinux-policy-targeted-3.7.19-231.el6_5.3.noarch.
> >
> > When moving from Permissive to Enforcing, two scripts in
> > /etc/cron.daily that use the bash "." operator to include a functions
> > file can no longer do so. The functions file sets $PATH and other
> > environment variables, so subsequent commands in the scripts fail.
> >
> > Interestingly, when run out of root's crontab, the scripts work
> > just fine. The context when doing that (gathered by placing id -Z in
> > the script) is:
> >
> > unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
> >
> > Not sure why; the script itself isn't unlabeled:
> >
> > bash-4.1# ls -lZ /usr/local/sbin/puppet-state
> > -rwx------. root root system_u:object_r:bin_t:s0
> > /usr/local/sbin/puppet-state
> >
> > When run from /etc/cron.daily (or cron.hourly, where I placed a
> > copy for faster testing), the context is:
> >
> > system_u:system_r:system_cronjob_t:s0-s0:c0.c1023
> >
> > bash-4.1# ls -lZ /etc/cron.hourly/puppet-state
> > -rwx------. root root system_u:object_r:bin_t:s0
> > /etc/cron.hourly/puppet-state
> >
> > The exact command in question it's failing to run is:
> >
> > . /opt/puppet/scripts/functions
> >
> > Which is labeled thusly:
> >
> > bash-4.1# ls -lZ /opt/puppet/scripts/functions
> > -r-x------. root root unconfined_u:object_r:usr_t:s0
> > /opt/puppet/scripts/functions
> >
> > In either Enforcing or Permissive, I wasn't seeing anything that
> > looked relevant, so I ran semodule -DB. This is the only thing cron-
> > related, but (and I'm not very experienced with SELinux, so maybe I'm
> > missing something) that doesn't seem like it:
> >
> > bash-4.1# cat /var/log/audit/audit.log-20140814 | grep cron |
> > audit2allow -w
> > type=AVC msg=audit(1407915503.212:155119): avc: denied {
> > rlimitinh } for pid=26239 comm="prelink"
> > scontext=system_u:system_r:prelink_cron_system_t:s0-s0:c0.c1023
> > tcontext=system_u:system_r:prelink_t:s0-s0:c0.c1023 tclass=process
> >
> > Was caused by:
> > Missing type enforcement (TE) allow rule.
> >
> > You can use audit2allow to generate a loadable
> > module to allow this access.
> >
> > type=AVC msg=audit(1407915503.212:155119): avc: denied { siginh
> > } for pid=26239 comm="prelink"
> > scontext=system_u:system_r:prelink_cron_system_t:s0-s0:c0.c1023
> > tcontext=system_u:system_r:prelink_t:s0-s0:c0.c1023 tclass=process
> >
> > Was caused by:
> > Missing type enforcement (TE) allow rule.
> >
> > You can use audit2allow to generate a loadable
> > module to allow this access.
> >
> > I suppose we could run them out of root's crontab, but they're
> > easier to manage in cron.daily, and I'd like to solve the problem. Any
> > assistance is greatly appreciated. A search of the list archives
> > didn't turn up this issue; sorry if I've missed it.
> >
> > --
> > Ray Shaw (Contractor, STG)
> > Army Research Laboratory
> >
> > Classification: UNCLASSIFIED
> > Caveats: NONE
> >
> >
> > --
> > selinux mailing list
> > selinux at lists.fedoraproject.org
> > https://admin.fedoraproject.org/mailman/listinfo/selinux
> >
> >
> >
> >
> > --
> >
> > Jeremy Young <mailto:jrm16020 at gmail.com> , M.S., RHCSA
> >
> >
>
>
> Classification: UNCLASSIFIED
> Caveats: NONE
>
>
>
> --
> selinux mailing list
> selinux at lists.fedoraproject.org
> https://admin.fedoraproject.org/mailman/listinfo/selinux
>
--
Jeremy Young <jrm16020 at gmail.com>, M.S., RHCSA
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