root vs system cron jobs (MLS_LEVEL)

[Nikolas Lam]

Hi

On Fedora 9, we've got a symlink in /etc/cron.daily/
to /usr/local/bin/checkmailspool which ultimately tries to run

	/usr/sbin/postqueue -p

It works if you call it via the root user's crontab, but not when you
put the script in /etc/cron.daily/. (I've included the sealert output
below).

When called by the "system" cron (in which the denial occurs) id -Z
output is

	system_u:system_r:system_crond_t:s0-s0:c0.c1023

OTOH, the root cron (which works) shows

	root:unconfined_r:unconfined_t:s0-s0:c0.c1023

I've just read crontab(5) which mentions setting MLS_LEVEL on the first
line of the crontab, but it seems to suggest that this would apply
(perhaps unnecessarily) to all the jobs run in that crontab.

What's the recommended method to get this one script working from
within /etc/cron.daily/ ?

Regards,

Nik Lam




Summary:

SELinux is preventing postqueue (postfix_postqueue_t) "connectto" to
/var/spool/postfix/public/showq (unconfined_t).

Detailed Description:

SELinux denied access requested by postqueue. It is not expected that
this
access is required by postqueue and this access may signal an intrusion
attempt.
It is also possible that the specific version or configuration of the
application is causing it to require additional access.

Allowing Access:

You can generate a local policy module to allow this access - see FAQ
(http://fedora.redhat.com/docs/selinux-faq-fc5/#id2961385) Or you can
disable
SELinux protection altogether. Disabling SELinux protection is not
recommended.
Please file a bug report
(http://bugzilla.redhat.com/bugzilla/enter_bug.cgi)
against this package.

Additional Information:

Source Context
system_u:system_r:postfix_postqueue_t:s0-s0:c0.c10
                              23
Target Context
unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Objects                /var/spool/postfix/public/showq [
                              unix_stream_socket ]
Source                        postqueue
Source Path                   /usr/sbin/postqueue
Port                          <Unknown>
Host                          replaced.example.com
Source RPM Packages           postfix-2.5.5-1.fc9
Target RPM Packages           
Policy RPM                    selinux-policy-3.3.1-107.fc9
Selinux Enabled               True
Policy Type                   targeted
MLS Enabled                   True
Enforcing Mode                Enforcing
Plugin Name                   catchall
Host Name                     replaced.example.com
Platform                      Linux replaced.example.com
                              2.6.25.14-108.fc9.i686 #1 SMP Mon Aug 4
14:08:11
                              EDT 2008 i686 i686
Alert Count                   38
First Seen                    Tue Nov  4 05:04:42 2008
Last Seen                     Thu Nov 20 05:04:42 2008
Local ID                      f5f4066b-d167-44ca-9c00-afd71f485225
Line Numbers                  

Raw Audit Messages

host=replaced.example.com type=AVC msg=audit(1227117882.675:17773): avc:
denied  { connectto } for  pid=15651 comm="postqueue"
path="/var/spool/postfix/public/showq"
scontext=system_u:system_r:postfix_postqueue_t:s0-s0:c0.c1023
tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
tclass=unix_stream_socket

host=replaced.example.com type=SYSCALL msg=audit(1227117882.675:17773):
arch=40000003 syscall=102 success=no exit=-13 a0=3 a1=bfa89e00
a2=b808eff4 a3=bfa89e6a items=0 ppid=15647 pid=15651 auid=0 uid=0 gid=0
euid=0 suid=0 fsuid=0 egid=90 sgid=90 fsgid=90 tty=(none) ses=2419
comm="postqueue" exe="/usr/sbin/postqueue"
subj=system_u:system_r:postfix_postqueue_t:s0-s0:c0.c1023 key=(null)