i386/120609: Kernel panic when using lighttpd, dev claims not their fault

[Simon Lundström]

>Number:         120609
>Category:       i386
>Synopsis:       Kernel panic when using lighttpd, dev claims not their fault
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Feb 13 09:20:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Simon Lundström
>Release:        5.4-STABLE
>Organization:
Stockholm University
>Environment:
FreeBSD storm.it.su.se 5.4-STABLE FreeBSD 5.4-STABLE #11: Thu Nov 24 15:14:58 CET 2005     root at lab18.lab.it.su.se:/usr/obj/afs/su.se/system/i386_fbsd5x/build-tree/src/sys/SU-GENERIC  i386
>Description:
I know that devs hate tickets like this one (I sure do), but I'd like some information about what might have gone wrong. Also, Jan Kneschke the lead developer of lighttpd requested this ticket since he have not recieved any similar ticket and noted that lighttpd should not cause a kernel panic since it isn't in the kernel and doing dangerous stuff (except using standard functions for this).

We are using lighttpd on a machine to only do HTTP redirects based on what IP it comes from and the machine kernel paniced one day (not ever since) with this message:

Kernel trap 12 with interrupts disabled

Fatal trap 12: page fault while in kernel mode
cpuid = 2; apic id = 06
fault virtual address		= 0x24
fault code					= supervisor read, page not present
instruction pointer			= 0x8:0xc063a11b
stack pointer				= 0x10:0xe8be3b74
frame pointer				= 0x10:0xe8be3b88
code segment				= base 0x0, limit 0xfffff, type 0x1b
							= DPL 0, pres 1, def32 1, gran 1
processor eflags			= resume, IOPL = 0
current process				= 26536 (lighttpd)
trap number					= 12
panic: page fault
cpuid = 2
spin lock sched lock held by 0xc349e688 for > 5 seconds
spin lock sched lock held by 0xc349e688 for > 5 seconds

I'm sorry if some of the info is incorrect, I took a photo of the monitor with my mobilephonecamera and it was a bit blurry. I tried my best to interpret it.
>How-To-Repeat:
Has not occurred since the problem first appeared.
>Fix:
None.

>Release-Note:
>Audit-Trail:
>Unformatted: