The permissions (rwx) don't change, but the uid/gid is mapped. E.g. uid 0 is the running user outside the container, by uid 1 will be mapped to 100000 (configur

The permissions (rwx) don't change, but the uid/gid is mapped. E.g. uid 0 is the running user outside the container, by uid 1 will be mapped to 100000 (configurable), and say 5000 inside the container is mapped to 105000. I don't remember the exact mapping but it works roughly like that.