A random speckle field is generated in the propagation of coherent light through a multimode fiber (MMF). For a non-polarization-maintaining MMF, linearly polarized incident light cannot maintain the linear polarization distribution owing to the depolarization effect. Therefore the randomness of the speckle pattern is observed in both intensity and polarization distributions. In this study, the intensity and polarization of the disordered speckle field generated by the MMF is controlled with the feedback wavefront shaping technology that generates a focal line with controllable polarization distribution.