/usr/share/doc/linux-tools-4.15.0-1008-oracle/changelog.Debian.gz is in linux-tools-4.15.0-1008-oracle 4.15.0-1008.10~16.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/linux-tools-4.15.0-1008-oracle/../linux-oracle-tools-4.15.0-1008/changelog.Debian.gz