---  sys/cam/cam_xpt.c.orig
+++  sys/cam/cam_xpt.c
@@ -5192,6 +5192,11 @@
 		/* Save some state for use while we probe for devices */
 		scan_info = (xpt_scan_bus_info *)
 		    malloc(sizeof(xpt_scan_bus_info), M_CAMXPT, M_NOWAIT);
+		if (scan_info == NULL) {
+			request_ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
+			xpt_done(request_ccb);
+			return;
+		}
 		scan_info->request_ccb = request_ccb;
 		scan_info->cpi = &work_ccb->cpi;