/usr/share/doc/libgstreamer-plugins-bad1.0-dev/changelog.Debian.gz is in libgstreamer-plugins-bad1.0-dev 1.2.3-1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgstreamer-plugins-bad1.0-dev/../libgstreamer-plugins-bad1.0-0/changelog.Debian.gz