[PATCH] SAK broken since 2.4.3

I wanted to show someone how nice SAK works, pressed it twice,
and lo! it not only killed the processes on the console, but
also the kernel. Very effective.

The patch below (for a private, patched 2.4.3 - line numbers
may differ) diminish this effectiveness a little. My kernel
now survives.

Andries

[PS I intend to come with another SAK patch one of these days,
but it may be for 2.5.]

--- tty_io.c~	Sat Mar 31 09:52:44 2001
+++ tty_io.c	Mon Jul  2 02:45:59 2001
@@ -1867,6 +1867,8 @@
  */
 void do_SAK(struct tty_struct *tty)
 {
+	if (!tty)
+		return;
 	PREPARE_TQUEUE(&tty->SAK_tq, __do_SAK, tty);
 	schedule_task(&tty->SAK_tq);
 }