--- src/sys/bus/cam/scsi/scsi_pt.c	2007/11/18 19:27:29	1.21
+++ src/sys/bus/cam/scsi/scsi_pt.c	2007/11/21 21:28:41	1.22
@@ -448,6 +448,8 @@ ptasync(void *callback_arg, u_int32_t co
 		cam_status status;
  
 		cgd = (struct ccb_getdev *)arg;
+		if (cgd == NULL)
+			break;
 
 		if (SID_TYPE(&cgd->inq_data) != T_PROCESSOR)
 			break;