  The irreducible upscattering of cold dark matter by cosmic rays opens up the
intriguing possibility of detecting even light dark matter in conventional
direct detection experiments or underground neutrino detectors. The mechanism
also significantly enhances sensitivity to models with very large nuclear
scattering rates, where the atmosphere and rock overburden efficiently stop
standard non-relativistic dark matter particles before they could reach the
detector. In this article, we demonstrate that cosmic-ray upscattering
essentially closes the window for strongly interacting dark matter in the
(sub-)GeV mass range. Arriving at this conclusion crucially requires a detailed
treatment of both nuclear form factors and inelastic dark matter-nucleus
scattering, as well as including the full momentum-transfer dependence of
scattering amplitudes. We illustrate the latter point by considering three
generic situations where such a momentum-dependence is particularly relevant,
namely for interactions dominated by the exchange of light vector or scalar
mediators, respectively, and for dark matter particles of finite size. As a
final concrete example, we apply our analysis to a putative hexaquark state,
which has been suggested as a viable baryonic dark matter candidate. Once
again, we find that the updated constraints derived in this work close a
significant part of otherwise unconstrained parameter space.
