What causes these odd glossy rough patches in my mesh?

I’ve completed my PS2 controller to the best of my ability. However since I began modeling it there have been these odd rough patches on the smooth shaded parts of the mesh.



What causes these and how can I fix them?

Probably some flaw in your topology. Without the .blend, it’s difficult to be more precise.

there’s probably a long triangle there.
(edit) which should be avoided.