Features:
+* system lsmbpf policy that prohibits creating files owned by "nobody"
+ system-wide
+
+* system lsmpbf policy that prohibits creating or opening device nodes outside
+ of devtmpfs/tmpfs, except if they are the pseudo-devices /dev/null,
+ /dev/zero, /dev/urandom and so on.
+
+* system lsmbpf policy that enforces that block device backed mounts may only
+ be established on top of dm-crypt or dm-verity devices, or an allowlist of
+ file systems (which should probably include vfat, for compat with the ESP)
+
* $LISTEN_PID, $MAINPID and $SYSTEMD_EXECPID env vars that the service manager
sets should be augmented with $LISTEN_PIDFDID, $MAINPIDFDID and
$SYSTEMD_EXECPIDFD (and similar for other env vars we might send).