port-i386/46237: starting npf causes a page fault

[bcorby%new-ms.com@localhost]

>Number:         46237
>Category:       port-i386
>Synopsis:       starting npf causes a page fault
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 22 03:00:01 +0000 2012
>Originator:     Ben Corby
>Release:        6.0_BETA
>Organization:
NMS
>Environment:
NetBSD  6.0_BETA NetBSD 6.0_BETA (GENERIC) #0: Thu Mar 22 09:47:35 EST 2012  
root@:/usr/obj/sys/arch/i386/compile/GENERIC i386
>Description:
After starting npf the system crashes with this:

uvm_fault(0xc0cfc7a0, 0 ,1> -> 0xe
fatal page fault in supervisor mode
trap type 6 code 0 eip c05566a1 cs 8 eflags 10282 cr2 14 ilevel 0
panic: trap
cpu0: Begin traceback...
printf_nolog(c0c09438,d7f11bb4,d7f11bb4,c05566a1,8,10282,14,0,c054749d,c19ff57e)
 at netbsd:printf_nolog
trap_tss() at netbsd:trap_tss
--- trap via task gate ---
npf:sess_lock:
cpu0: End traceback...

dump to dev 0,1 not possible
rebooting...
>How-To-Repeat:
To reproduce:
1) install a clean system
2) as root type "npfctl start"
3) wait a few seconds for the crash


>Fix: