The problem here is that there is a different selinux check for unit file in rhel. We need a general fix here.

I can't reproduce this on my machine using systemd-219:

# cat /etc/os-release 
NAME="Red Hat Enterprise Linux Workstation"
VERSION="7.1 (Maipo)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="7.1"
PRETTY_NAME="Red Hat Enterprise Linux Workstation 7.1 (Maipo)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:7.1:GA:workstation"
HOME_URL="https://www.redhat.com/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 7"
REDHAT_BUGZILLA_PRODUCT_VERSION=7.1
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="7.1"

# sestatus 
SELinux status:                 enabled
SELinuxfs mount:                /sys/fs/selinux
SELinux root directory:         /etc/selinux
Loaded policy name:             targeted
Current mode:                   enforcing
Mode from config file:          enforcing
Policy MLS status:              enabled
Policy deny_unknown status:     allowed
Max kernel policy version:      28

# systemctl enable non-existent.service
Failed to execute operation: No such file or directory

# systemctl status non-existent.service                          
● non-existent.service
   Loaded: not-found (Reason: No such file or directory)
   Active: inactive (dead)

Maybe my SELinux policy is missing something?

Relevant strace output:

sendmsg(3, {msg_name(0)=NULL, msg_iov(2)=[{"l\1\0\1(\0\0\0\1\0\0\0\242\0\0\0\1\1o\0\31\0\0\0/org/freedesktop/systemd1\0\0\0\0\0\0\0\6\1s\0\30\0\0\0org.freedesktop.systemd1\0\0\0\0\0\0\0\0\2\1s\0 \0\0\0org.freedesktop.systemd1.Manager\0\0\0\0\0\0\0\0\3\1s\0\17\0\0\0EnableUnitFiles\0\10\1g\0\4asbb\0\0\0\0\0\0\0", 184}, {"\31\0\0\0\24\0\0\0non-existent.service\0\0\0\0\0\0\0\0\0\0\0\0", 40}], msg_controllen=0, msg_flags=0}, MSG_NOSIGNAL) = 224
poll([{fd=3, events=POLLIN}], 1, 25000) = 1 ([{fd=3, revents=POLLIN}])
recvmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{"l\3\1\1\"\0\0\0\1\0\0\0?\0\0\0\4\1s\0'\0\0\0org.freedesktop.DBus.Error.AccessDenied\0\5\1u\0\1\0\0\0\10\1g\0\1s\0\0\35\0\0\0SELinux policy denies access.\0l\4\1\1X\0\0\0\210\1\0\0p\0\0\0\1\1o\0\31\0\0\0/org/freedesktop/systemd1\0\0\0\0\0\0\0\2\1s\0 \0\0\0org.freedesktop.systemd1.Manager\0\0\0\0\0\0\0\0\3\1s\0\7\0\0\0UnitNew\0\10\1g\0\2so\0\24\0\0\0non-existent.service\0\0\0\0007\0\0\0/org/freedesktop/systemd1/unit/non_2dexistent_2eservice\0l\4\1\1X\0\0\0\211\1\0\0x\0\0\0\1\1o\0\31\0\0\0/org/freedesktop/systemd1\0\0\0\0\0\0\0\2\1s\0 \0\0\0org.freedesktop.systemd1.Manager\0\0\0\0\0\0\0\0\3\1s\0\v\0\0\0UnitRemoved\0\0\0\0\0\10\1g\0\2so\0\24\0\0\0non-existent.service\0\0\0\0007\0\0\0/org/freedesktop/systemd1/unit/non_2dexistent_2eservice\0", 2048}], msg_controllen=0, msg_flags=MSG_CMSG_CLOEXEC}, MSG_CMSG_CLOEXEC) = 554
recvmsg(3, 0x7fff96daec60, MSG_CMSG_CLOEXEC) = -1 EAGAIN (Resource temporarily unavailable)
writev(2, [{"Failed to issue method call: Access denied", 42}, {"\n", 1}], 2Failed to issue method call: Access denied


# tail -n 1 /var/log/audit/audit.log
type=USER_AVC msg=audit(1432574062.941:64): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='avc:  denied  { enable } for auid=0 uid=0 gid=0 cmdline="systemctl enable non-existent.service" scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=system_u:system_r:init_t:s0 tclass=service  exe="/usr/lib/systemd/systemd" sauid=0 hostname=? addr=? terminal=?'

# id -Z
unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

# systemctl enable this-does-not-exist.service
Failed to issue method call: Access denied

# yum update
No packages marked for update

# audit2allow -a -M systemctl-enable

# semodule -i systemctl-enable.pp 

# systemctl enable non-existent.service
Failed to issue method call: No such file or directory

(In reply to Giovanni Tirloni from comment #4)
> Maybe my SELinux policy is missing something?

To be more explicit - I *can* reproduce this with the systemd version currently in RHEL-7.1:

# rpm -q systemd
systemd-208-20.el7.x86_64

I can *not* reproduce this with our testing RHEL-7.2 build of systemd-219, that can be found in COPR:

https://copr.fedoraproject.org/coprs/lnykryn/systemd/

This bug will be fixed by the update.

Created attachment 1050881 [details]
0001-Retrict-org.freedesktop.DBus.Properties-interface-to.patch

Wrong bugreport *sigh*

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-2092.html