Subject: kern/24719: bktr(4) can freeze a machine
To: None <>
From: None <>
List: netbsd-bugs
Date: 03/09/2004 16:30:56
>Number:         24719
>Category:       kern
>Synopsis:       bktr(4) can freeze a machine
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Mar 09 15:29:00 UTC 2004
>Originator:     Julio M. Merino Vidal
>Release:        NetBSD 1.6ZK
Julio M. Merino Vidal <>
The NetBSD Project -
System: NetBSD dawn.local 1.6ZK NetBSD 1.6ZK (DAWN) #2: Fri Mar 5 14:40:28 CET 2004 jmmv@dawn.local:/home/build/obj/usr/src/sys/arch/i386/compile/DAWN i386
Architecture: i386
Machine: i386
	The bktr(4) driver can completely freeze a -current system.  When you
	are watching the TV in overlay mode, just move the application window
	out of the left border of the screen and it gets freezed.

	This does not happen when moving the window out of the top, nor right,
	nor bottom borders of the screen.

	It seems that the kernel enters an infinite loop or some kind of thing
	(I can hear the CPU usage increases a lot; yes, hear ;), though ddb
	can be entered and 'sync' causes a core dump (did it blindly, since I
	can't get out of X11, but the core file was written and I have it
	available if needed).

	Just FYI, this is an Avermedia TV Phone (not 98), though I guess this
	doesn't matter:

	bktr0 at pci0 dev 11 function 0
	bktr0: interrupting at ioapic0 pin 19 (irq 3)
	bktr0: AVer Media TV/FM, Philips FR1216 PAL FM tuner.
	radio0 at bktr0
	1) Start xawtv.
	2) Drag the window through the left side of your screen.
	3) See how the computer freezes.
	Unfortunately, unknown.