bin/59257: modified fire_saver can halt kernel

[Charlie &]

>Number:         59257
>Category:       bin
>Synopsis:       modified fire_saver can halt kernel
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Nov 13 10:00:36 PST 2003
>Closed-Date:
>Last-Modified:
>Originator:     Charlie &
>Release:        FreeBSD 4.9-STABLE i386
>Organization:
>Environment:
>Description:
	While fooling around with fire_saver.c I've found that changing the Y_SIZE during the iteration in the /* fade the flames out */ you can effectively crash the system
This is quite undesireable, since a total system halt, without a single warning is not so good. It's not good to crash OS with software.

>How-To-Repeat:
	Change the following lines
        /* fade the flames out
        for (y = 0; y < Y_SIZE; y++) {
to
        /* fade the flames out
        for (y = 0; y < Y_SIZE+10; y++) {

kldunload fire_saver; kldload fire_saver

>Fix:
	Don't increase Y_SIZE.


>Release-Note:
>Audit-Trail:
>Unformatted:
 >System: FreeBSD ntest.nnnnn.com 4.9-STABLE FreeBSD 4.9-STABLE #0: Wed Nov 12 19:00:06 PST 2003 root at ntest.nnnnnn.com:/usr/obj/usr/src/sys/NTEST i386
 
 	<machine, os, target, libraries (multiple lines)>