units: lock down systemd-logind.service with various fs namespacing options

now that logind doesn't mount $XDG_RUNTIME_DIR anymore we can lock down
the service using fs namespacing (as we don't need the mount to
propagate to the host namespace anymore).

diff --git a/units/systemd-logind.service.in b/units/systemd-logind.service.in
index ff1fd96..6886fa9 100644 (file)
--- a/units/systemd-logind.service.in
+++ b/units/systemd-logind.service.in
@@ -28,11 +28,19 @@ IPAddressDeny=any
 LockPersonality=yes
 MemoryDenyWriteExecute=yes
 NoNewPrivileges=yes
+PrivateTmp=yes
+ProtectControlGroups=yes
+ProtectHome=yes
+ProtectKernelModules=yes
+ProtectSystem=strict
+ReadWritePaths=/etc
 Restart=always
 RestartSec=0
 RestrictAddressFamilies=AF_UNIX AF_NETLINK
 RestrictNamespaces=yes
 RestrictRealtime=yes
+RuntimeDirectory=systemd/sessions systemd/seats systemd/users
+RuntimeDirectoryPreserve=yes
 SystemCallArchitectures=native
 SystemCallErrorNumber=EPERM
 SystemCallFilter=@system-service