int drm_mode_group_init_legacy_group(struct drm_device *dev,
				     struct drm_mode_group *group)
{
	struct drm_crtc *crtc;
	struct drm_encoder *encoder;
	struct drm_connector *connector;
	int ret;

	if ((ret = drm_mode_group_init(dev, group)))
		return ret;

	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
		group->id_list[group->num_crtcs++] = crtc->base.id;

	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
		group->id_list[group->num_crtcs + group->num_encoders++] =
		encoder->base.id;

	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
		group->id_list[group->num_crtcs + group->num_encoders +
			       group->num_connectors++] = connector->base.id;

	return 0;
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.