Needs a thin adapter
Canon EF-M and Sony E sit at exactly the same distance from the sensor (18.00mm), so focus is preserved by a flush adapter that adds no length — a thin ring rather than a tube. These pairings usually have cheap, widely available adapters.
Coverage & framing. Canon EF-M lenses are built for a APS-C imaging circle, which is smaller than Full frame. Expect heavy vignetting or a forced crop on a Sony E body.