Description of problem:

SELinux is preventing 706F737467726579202D2D756E6978 from using the dac_override capability.

*****  Plugin dac_override (91.4 confidence) suggests   **********************

If you want to help identify if domain needs this access or you have a file with the wrong permissions on your system
Then turn on full auditing to get path information about the offending file and generate the error again.
Do

Turn on full auditing
# auditctl -w /etc/shadow -p w
Try to recreate AVC. Then execute
# ausearch -m avc -ts recent
If you see PATH record check ownership/permissions on file, and fix it,
otherwise report as a bugzilla.

*****  Plugin catchall (9.59 confidence) suggests   **************************

If you believe that 706F737467726579202D2D756E6978 should have the dac_override capability by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# ausearch -c '706F737467726579202D2D756E6978' --raw | audit2allow -M my-706F737467726579202D2D756E6978
# semodule -X 300 -i my-706F737467726579202D2D756E6978.pp


Additional Information:
Source Context                system_u:system_r:postgrey_t:s0
Target Context                system_u:system_r:postgrey_t:s0
Target Objects                Unknown [ capability ]
Source                        706F737467726579202D2D756E6978
Source Path                   706F737467726579202D2D756E6978
Port                          <Unknown>
Host                          <Unknown>
Source RPM Packages           
Target RPM Packages           
Policy RPM                    selinux-policy-3.14.1-44.fc28.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     nym
Platform                      Linux nym 4.18.12-200.fc28.x86_64 #1 SMP Thu Oct 4
                              15:46:35 UTC 2018 x86_64 x86_64
Alert Count                   20
First Seen                    2018-10-12 21:16:26 UTC
Last Seen                     2018-10-13 12:05:06 UTC
Local ID                      e1fc36dd-a577-4b02-9551-f81cbdfbf73f

Raw Audit Messages
type=AVC msg=audit(1539432306.51:606): avc:  denied  { dac_override } for  pid=2366 comm=706F737467726579202D2D756E6978 capability=1  scontext=system_u:system_r:postgrey_t:s0 tcontext=system_u:system_r:postgrey_t:s0 tclass=capability permissive=0


Hash: 706F737467726579202D2D756E6978,postgrey_t,postgrey_t,capability,dac_override



Version-Release number of selected component (if applicable):

postgrey-1.37-4.fc28.noarch
selinux-policy-3.14.1-44.fc28.noarch

How reproducible:

Always

Steps to Reproduce:
1. systemctl start postgrey.service

Actual results:

postgrey fails to start.

From journalctl:

Oct 13 12:05:06 nym postgrey[2366]: 2018/10/13-12:05:06 postgrey (type Net::Serv
er::Multiplex) starting! pid(2366)
Oct 13 12:05:06 nym systemd[1]: Started Postfix Greylisting Service.
Oct 13 12:05:06 nym audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294
967295 subj=system_u:system_r:init_t:s0 msg='unit=postgrey comm="systemd" exe="/
usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
Oct 13 12:05:06 nym audit[2366]: AVC avc:  denied  { dac_override } for  pid=236
6 comm=706F737467726579202D2D756E6978 capability=1  scontext=system_u:system_r:p
ostgrey_t:s0 tcontext=system_u:system_r:postgrey_t:s0 tclass=capability permissi
ve=0
Oct 13 12:05:06 nym postgrey[2366]: Binding to UNIX socket file "/var/spool/post
fix/postgrey/socket"
Oct 13 12:05:06 nym postgrey[2366]: FATAL: ERROR: Can't connect to UNIX socket a
t file /var/spool/postfix/postgrey/socket [Permission denied] at /usr/sbin/postg
rey line 788.
Oct 13 12:05:06 nym systemd[1]: postgrey.service: Main process exited, code=exit
ed, status=13/n/a
Oct 13 12:05:06 nym audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=42949
67295 subj=system_u:system_r:init_t:s0 msg='unit=postgrey comm="systemd" exe="/u
sr/lib/systemd/systemd" hostname=? addr=? terminal=? res=failed'
Oct 13 12:05:06 nym systemd[1]: postgrey.service: Failed with result 'exit-code'
.

Expected results:

postgrey starts successfullyprevent


Additional info: