pdf14_clist_fill_path(gx_device	*dev, const gs_gstate *pgs,
                           gx_path *ppath, const gx_fill_params *params,
                           const gx_drawing_color *pdcolor,
                           const gx_clip_path *pcpath)
{
    pdf14_clist_device * pdev = (pdf14_clist_device *)dev;
    gs_gstate new_pgs = *pgs;
    int code;
    gs_pattern2_instance_t *pinst = NULL;
    gx_device_forward * fdev = (gx_device_forward *)dev;
    cmm_dev_profile_t *dev_profile, *fwd_profile;
    gsicc_rendering_param_t render_cond;
    cmm_profile_t *icc_profile_fwd, *icc_profile_dev;

    code = dev_proc(dev, get_profile)(dev,  &dev_profile);
    if (code < 0)
        return code;
    code = dev_proc(fdev->target, get_profile)(fdev->target,  &fwd_profile);
    if (code < 0)
        return code;

    gsicc_extract_profile(GS_UNKNOWN_TAG, fwd_profile, &icc_profile_fwd,
                          &render_cond);
    gsicc_extract_profile(GS_UNKNOWN_TAG, dev_profile, &icc_profile_dev,
                          &render_cond);

    /*
     * Ensure that that the PDF 1.4 reading compositor will have the current
     * blending parameters.  This is needed since the fill_rectangle routines
     * do not have access to the gs_gstate.  Thus we have to pass any
     * changes explictly.
     */
    code = pdf14_clist_update_params(pdev, pgs, false, NULL);
    if (code < 0)
        return code;
    /* If we are doing a shading fill and we are in a transparency group of a
       different color space, then we do not want to do the shading in the
       device color space. It must occur in the source space.  To handle it in
       the device space would require knowing all the nested transparency group
       color space as well as the transparency.  Some of the shading code ignores
       this, so we have to pass on the clist_writer device to enable proper
       mapping to the transparency group color space. */

    if (pdcolor != NULL && gx_dc_is_pattern2_color(pdcolor)) {
        pinst =
            (gs_pattern2_instance_t *)pdcolor->ccolor.pattern;
           pinst->saved->has_transparency = true;
           /* The transparency color space operations are driven by the pdf14
              clist writer device.  */
           pinst->saved->trans_device = dev;
    }
    update_lop_for_pdf14(&new_pgs, pdcolor);
    new_pgs.trans_device = dev;
    new_pgs.has_transparency = true;
    code = gx_forward_fill_path(dev, &new_pgs, ppath, params, pdcolor, pcpath);
    new_pgs.trans_device = NULL;
    new_pgs.has_transparency = false;
    if (pinst != NULL){
        pinst->saved->trans_device = NULL;
    }
    return code;
}

The product dereferences a pointer that it expects to be valid but is NULL.