kern/148050: 9.0-CURRENT panic when tcpdump ipfw0 and net.inet.ip.fw.verbose=0

[Oleg Ginzburg]

>Number:         148050
>Category:       kern
>Synopsis:       9.0-CURRENT panic when tcpdump ipfw0 and net.inet.ip.fw.verbose=0
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jun 21 21:30:01 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator:     Oleg Ginzburg
>Release:        9.0-CURRENT
>Organization:
>Environment:
FreeBSD localhost.my.domain 9.0-CURRENT FreeBSD 9.0-CURRENT #5: Sun Jun 20 18:48:44 MSD 2010     root at localhost.my.domain:/usr/obj/usr/src/sys/GENERIC-NODEBUG  amd64

>Description:
kernel make panic with messages:

panic: page fault
panic: bufwrite : buffer is not busy?

when IPFIREWALL_VERBOSE disable, ipfw have log options and tcpdump looking to ipfw0 interface

I've producible this problem on amd64 and i386 (both 9.0-CURRENT)
>How-To-Repeat:
kldload ipfw
sysctl -w net.inet.ip.fw.verbose=0
ipfw add 1 count log ip from any to any
tcpdump -n -i ipfw0 &
ping -c1 localhost

>Fix:


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