IS it possible to have total bound current NOT equal to 0?

I have a permanent magnetization [itex]\vec{M}[/itex]=(ks)[itex]\hat{z}[/itex], k is just a const, s is the cylindrical coor. Then it turns out that the total bound current not equal to 0. i wonder is it possible? the magnetization is stored inside the shell of a cylinder of inner radius a and outer radius b.
thanks in advance!