kern/43664: fragmentation on lo0 causes panic

[mlelstv%serpens.de@localhost]

>Number:         43664
>Category:       kern
>Synopsis:       fragmentation on lo0 causes panic
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jul 25 12:40:01 +0000 2010
>Originator:     Michael van Elst
>Release:        NetBSD-current
>Organization:
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."
>Environment:
        
        
System: NetBSD pussyfoot 5.99.36 NetBSD 5.99.36 (PUSSYFOOT) #117: Sat Jul 24 
08:09:32 CEST 2010 
mlelstv@henery:/home/netbsd-current/obj.amd64/home/netbsd-current/src/sys/arch/amd64/compile/PUSSYFOOT
 amd64
Architecture: x86_64
Machine: amd64
>Description:
I tried to cause IP fragmentation on the loopback interface and it
panics reproducably with

panic: kernel diagnostic assertion "m->m_pkthdr.csum_flags & M_CSUM_IPv4" 
failed: file "/home/netbsd-current/src/sys/netinet/ip_output.c", line 1033

>How-To-Repeat:

ifconfig lo0 mtu 100
route change 127.0.0.1 -mtu 100
ping -s 500 127.0.0.1

>Fix:
        

>Unformatted: