postfix fifo file

[Daniel J Walsh]

On 04/09/2009 11:44 AM, Craig White wrote:
> This is from a newly setup CentOS 5.3 server...and I definitely don't
> understand what it's wanting to make it happy.
>
> # sealert -l 6208be6e-3fb4-4748-80e8-769687066b83
>
> Summary:
>
> SELinux is preventing postfix-script (postfix_master_t) "ioctl" to pipe
> (crond_t).
>
> Detailed Description:
>
> [SELinux is in permissive mode, the operation would have been denied but
> was permitted due to permissive mode.]
>
> SELinux denied access requested by postfix-script. It is not expected
> that this access is required by postfix-script 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                user_u:system_r:postfix_master_t
> Target Context
> system_u:system_r:crond_t:SystemLow-SystemHigh
> Target Objects                pipe [ fifo_file ]
> Source                        postfix-script
> Source Path                   /bin/bash
> Port<Unknown>
> Host                          srv1.azapple.com
> Source RPM Packages           bash-3.2-24.el5
> Target RPM Packages
> Policy RPM                    selinux-policy-2.4.6-203.el5
> Selinux Enabled               True
> Policy Type                   targeted
> MLS Enabled                   True
> Enforcing Mode                Permissive
> Plugin Name                   catchall
> Host Name                     srv1.azapple.com
> Platform                      Linux srv1.azapple.com 2.6.18-128.1.1.el5
> #1 SMP
>                                Wed Mar 25 18:15:30 EDT 2009 i686 i686
> Alert Count                   8
> First Seen                    Thu Apr  2 04:34:40 2009
> Last Seen                     Thu Apr  9 04:17:20 2009
> Local ID                      6208be6e-3fb4-4748-80e8-769687066b83
> Line Numbers
>
> Raw Audit Messages
>
> host=srv1.azapple.com type=AVC msg=audit(1239275840.489:3152): avc:
> denied  { ioctl } for  pid=11778 comm="postfix-script"
> path="pipe:[1634010]" dev=pipefs ino=1634010
> scontext=user_u:system_r:postfix_master_t:s0
> tcontext=system_u:system_r:crond_t:s0-s0:c0.c1023 tclass=fifo_file
>
> host=srv1.azapple.com type=SYSCALL msg=audit(1239275840.489:3152):
> arch=40000003 syscall=54 success=no exit=-22 a0=0 a1=5401 a2=bfc30d40
> a3=bfc30e4c items=0 ppid=11761 pid=11778 auid=0 uid=0 gid=0 euid=0
> suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=212
> comm="postfix-script" exe="/bin/bash"
> subj=user_u:system_r:postfix_master_t:s0 key=(null)
>
>
>
This look like postfix trying to communicate with the pipe from cron 
(stdout).  Current policy allows read/write/getattr but no ioctl.

You can add this access via
# grep postfix /var/log/audit/audit.log | audit2allow -mypostfix
# semodule -i mypostfix.pp

I will add this fix to RHEL5.4 policy, Preview should be available on

http://people.redhat.com/dwalsh/SELinux/RHEL5

selinux-policy-2.4.6-223.el5