Description of problem:
Having libvirt-nss installed and enabled in nsswitch.conf seems to continuously cause AVC denials when NetworkManager wants to access libvirt's own dnsmasq.

This is very likely a dupe of bug #1507110
SELinux is preventing NetworkManager from 'read' accesses on the directory /var/lib/libvirt/dnsmasq.

*****  Plugin catchall (100. confidence) suggests   **************************

If you believe that NetworkManager should be allowed read access on the dnsmasq directory 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 'NetworkManager' --raw | audit2allow -M my-NetworkManager
# semodule -X 300 -i my-NetworkManager.pp

Additional Information:
Source Context                system_u:system_r:NetworkManager_t:s0
Target Context                system_u:object_r:virt_var_lib_t:s0
Target Objects                /var/lib/libvirt/dnsmasq [ dir ]
Source                        NetworkManager
Source Path                   NetworkManager
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           
Target RPM Packages           libvirt-daemon-driver-network-3.7.0-3.fc27.x86_64
Policy RPM                    selinux-policy-3.13.1-283.19.fc27.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 4.14.11-300.fc27.x86_64 #1 SMP Wed
                              Jan 3 13:52:28 UTC 2018 x86_64 x86_64
Alert Count                   18
First Seen                    2017-12-20 10:36:07 EET
Last Seen                     2018-01-05 10:38:23 EET
Local ID                      57f7f37f-68b5-4c54-a53b-c26a382c4bba

Raw Audit Messages
type=AVC msg=audit(1515141503.843:370): avc:  denied  { read } for  pid=1889 comm="NetworkManager" name="dnsmasq" dev="dm-1" ino=1710671 scontext=system_u:system_r:NetworkManager_t:s0 tcontext=system_u:object_r:virt_var_lib_t:s0 tclass=dir permissive=0


Hash: NetworkManager,NetworkManager_t,virt_var_lib_t,dir,read

Version-Release number of selected component:
selinux-policy-3.13.1-283.19.fc27.noarch

Additional info:
component:      selinux-policy
reporter:       libreport-2.9.3
hashmarkername: setroubleshoot
kernel:         4.14.13-300.fc27.x86_64
type:           libreport

Potential duplicate: bug 1507110