A Jazzmaster neck can fit onto a Stratocaster body, but it is not a direct bolt-on and may require some modification.
The mounting holes on a Jazzmaster neck are different than those on a Stratocaster body, so you will need to drill new holes or fill the existing ones before attaching the neck.
Additionally, the neck pocket on a Stratocaster body is different in shape and size than that on a Jazzmaster body, so some additional routing or shaping may be necessary to ensure a proper fit.
Also, the radius of the fingerboard, the scale length, the nut width, and the truss rod adjustments may be different between the two models, and that would affect playability and intonation.
Therefore, it is recommended to consult a professional luthier or guitar technician before attempting this modification.
