kern/47062: panic: kernel diagnostic assertion "lwpcnt >= 0" failed: file "/usr/src/sys/kern/kern_uidinfo.c", line 217

[roy%marples.name@localhost]

>Number:         47062
>Category:       kern
>Synopsis:       panic: kernel diagnostic assertion "lwpcnt >= 0" failed: file 
>"/usr/src/sys/kern/kern_uidinfo.c", line 217
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Oct 12 13:50:00 +0000 2012
>Originator:     Roy Marples
>Release:        -current
>Organization:
>Environment:
NetBSD uberlaptop 6.99.12 NetBSD 6.99.12 (GENERIC) #1: Wed Oct 10 19:16:47 BST 
2012  roy@uberlaptop:/usr/obj/sys/arch/i386/compile/GENERIC i386
>Description:
panic: kernel diagnostic assertion "lwpcnt >= 0" failed: file 
"/usr/src/sys/kern/kern_uidinfo.c", line 217
cpu0: Begin traceback...
kern_assert(c0e50024,c0e50016,c0e50058,c0e4ffe8,d9,ffffffff,c23d21b0,db151bd0,c06d2ba6,0)
 at netbsd:kern_assert+0x27
chglwpcnt(0,ffffffff,c06d7df7,0,471b40,db151b00,db151b00,c32b7540,c32b7540,db151bd0)
 at netbsd:chglwpcnt+0x64
lwp_free(c3364d40,0,0,c06f4f5e,c3364d40,c32b7501,c32b8a2c,1,0,c06c7ed6) at 
netbsd:lwp_free+0xf1
lwp_wait(c32b7540,0,0,1,db151c2c,0,c32b8a2c,0,db151cb4,c06c815b) at 
netbsd:lwp_wait+0x10c
exit_lwps(c32b7540,c2919480,1,c32b4500,c32b4400,1,db151c98,c0a1d8d9,4,2) at 
netbsd:exit_lwps+0x129
exit1(c32b7540,100,c32b8a2c,db151ce0,c0a2c907,c32b7540,db151cf8,db151d20,0,db151d3c)
 at netbsd:exit1+0xf8
exit1(c32b7540,db151cf8,db151d20,0,db151d3c,c0a2cc21,c0f94f6c,c32b7540,db151cf8,db151d20)
 at netbsd:exit1
sy_call(c0f94f6c,c32b7540,db151cf8,db151d20,1,bbacaff4,bfbfec90,bba9de4b,c32b7540,2)
 at netbsd:sy_call+0x2e
syscall() at netbsd:syscall+0x12b
--- syscall (number 1) ---
bba439a7:
cpu0: End traceback...

>How-To-Repeat:
Just reboot -current on an x86 :)
>Fix: