/usr/lib/x86_64-linux-gnu/liblttng-ust-ctl.so is in liblttng-ust-dev 2.10.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/liblttng-ust-ctl.so.4.0.0
/usr/lib/x86_64-linux-gnu/liblttng-ust-ctl.so.4.0.0