  We present magnetoresistivity measurements in high-quality single crystals of
the Nowotny chimney ladder compound Ru$_2$Sn$_3$. We find a linear and
nonsaturating magnetoresistance up to 20 T. The magnetoresistance changes with
the magnetic field orientation at small magnetic fields, from a positive to a
negative curvature. Above 5 T, the magnetoresistance shows no sign of
saturation up to 20 T for any measured angle. The shape of the anisotropy in
the magnetoresistance remains when increasing temperature and Kohler's rule is
obeyed. We associate the linear and nonsaturating magnetoresistance to a small
Fermi surface with hot spots, possibly formed as a consequence of the
structural transition. We discuss the relevance of electron-electron
interactions under magnetic fields and aspects of the topologically nontrivial
properties expected in Ru$_2$Sn$_3$.
