logrotate: potential DoS from unprivileged users via the state file

A vulnerability was found in logrotate in how the state file is created. The state file is used to prevent parallel executions of multiple instances of logrotate by acquiring and releasing a file lock. When the state file does not exist, it is created with world-readable permission, allowing an unprivileged user to lock the state file, stopping any rotation. This flaw affects logrotate versions before 3.20.0.