diff -Naur linux-2.6.10-mm2.orig/arch/um/drivers/line.c linux-2.6.10-mm2/arch/um/drivers/line.c
--- linux-2.6.10-mm2.orig/arch/um/drivers/line.c	2005-01-10 14:35:20.379815252 -0700
+++ linux-2.6.10-mm2/arch/um/drivers/line.c	2005-01-10 14:35:59.786829555 -0700
@@ -593,8 +593,8 @@
 		}
 	}
 	tty  = winch->tty;
-	line = tty->driver_data;
 	if (tty != NULL) {
+		line = tty->driver_data;
 		chan_window_size(&line->chan_list,
 				 &tty->winsize.ws_row, 
 				 &tty->winsize.ws_col);