Description of problem:
SELinux is preventing systemd from 'associate' accesses on the shared memory Unknown.

*****  Plugin associate (99.5 confidence) suggests   *************************

If you want to change the label of Unknown to init_t, you are not allowed to since it is not a valid file type.
Then you must pick a valid file label.
Do
select a valid file type.  List valid file labels by executing: 
# seinfo -afile_type -x

*****  Plugin catchall (1.49 confidence) suggests   **************************

If you believe that systemd should be allowed associate access on the Unknown shm 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 'systemd' --raw | audit2allow -M my-systemd
# semodule -X 300 -i my-systemd.pp

Additional Information:
Source Context                system_u:system_r:init_t:s0
Target Context                system_u:system_r:unconfined_service_t:s0
Target Objects                Unknown [ shm ]
Source                        systemd
Source Path                   systemd
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           
Target RPM Packages           
Policy RPM                    selinux-policy-3.13.1-224.fc25.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 4.8.8-300.fc25.x86_64 #1 SMP Tue
                              Nov 15 18:10:06 UTC 2016 x86_64 x86_64
Alert Count                   11904
First Seen                    2016-11-22 21:18:28 CET
Last Seen                     2016-12-01 18:09:11 CET
Local ID                      f26fe15b-2433-49b9-8a8d-5e9ca76bd85c

Raw Audit Messages
type=AVC msg=audit(1480612151.664:237450): avc:  denied  { associate } for  pid=1 comm="systemd" key=838864853  scontext=system_u:system_r:init_t:s0 tcontext=system_u:system_r:unconfined_service_t:s0 tclass=shm permissive=0


Hash: systemd,init_t,unconfined_service_t,shm,associate

Version-Release number of selected component:
selinux-policy-3.13.1-224.fc25.noarch

Additional info:
reporter:       libreport-2.8.0
hashmarkername: setroubleshoot
kernel:         4.8.8-300.fc25.x86_64
type:           libreport