/usr/include/samba-4.0/util/ is in samba-dev 2:4.7.6+dfsg~ubuntu-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/samba-4.0/util/attr.h
/usr/include/samba-4.0/util/blocking.h
/usr/include/samba-4.0/util/byteorder.h
/usr/include/samba-4.0/util/data_blob.h
/usr/include/samba-4.0/util/debug.h
/usr/include/samba-4.0/util/fault.h
/usr/include/samba-4.0/util/genrand.h
/usr/include/samba-4.0/util/idtree.h
/usr/include/samba-4.0/util/idtree_random.h
/usr/include/samba-4.0/util/memory.h
/usr/include/samba-4.0/util/safe_string.h
/usr/include/samba-4.0/util/signal.h
/usr/include/samba-4.0/util/string_wrappers.h
/usr/include/samba-4.0/util/substitute.h
/usr/include/samba-4.0/util/talloc_stack.h
/usr/include/samba-4.0/util/tevent_ntstatus.h
/usr/include/samba-4.0/util/tevent_unix.h
/usr/include/samba-4.0/util/tevent_werror.h
/usr/include/samba-4.0/util/tfork.h
/usr/include/samba-4.0/util/time.h