  It is well known that linear vector fields defined in $\mathbb{R}^n$ can not
have limit cycles, but this is not the case for linear vector fields defined in
other manifolds. We study the existence of limit cycles bifurcating from a
continuum of periodic orbits of linear vector fields on manifolds of the form
$(\mathbb{S}^2)^m \times \mathbb{R}^n$ when such vector fields are perturbed
inside the class of all linear vector fields. The study is done using the
averaging theory. We also present an open problem concerning the maximum number
of limit cycles of linear vector fields on $(\mathbb{S}^2)^m \times
\mathbb{R}^n$.
