/usr/share/xml/docbook/schema/dtd/4.0/dbgenent.ent is in docbook-xml 4.5-7.3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /etc/sgml/docbook-xml/4.0/dbgenent.ent
/etc/sgml/docbook-xml/4.0/dbgenent.ent