/usr/share/java/maven-javadoc-plugin.jar is in libmaven-javadoc-plugin-java 2.6.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/java/../maven-repo/org/apache/maven/plugins/maven-javadoc-plugin/2.6.1/maven-javadoc-plugin-2.6.1.jar