While it is conforming to have multiple label elements pointing to a single control for labelling purposes, it is not recommended. It has been conforming as per (X)HTML specifications for many years, but it is not robustly supported. Other techniques such as wrapping the label around text and control and aria-labelledby do the job better and are much better supported in modern browsers and assistive technology.
multiple labels for a control using the label element
Notes, examples and recommendations