MROUTING issues (r200287) with multicast routing daemons

Hello, hope you're having a nice day,

I have a problem with my single-core amd64 system running FreeBSD
8.0-STABLE #1 r200287; if I try running XORP (or igmpproxy) to route
multicast packets, the system traps after a while - usually less than a
hour since the start of xorp process. This is, basically, easily
reproductable for me. The routing daemon is configured to route
multicast from the external interface re0, which is currently not
connected ('no carrier').

Traps seemingly occur within ip_mroute.c. The process in which the crash
occurs varies; it might be xorp's FEA subprocess, or the system's
interrupt handler, for example (I witnessed both).

The following lines were added to the kernel config file:

device          pf
device          pflog
device          pfsync
options         ALTQ
options         ALTQ_HFSC
options         DEVICE_POLLING
options         MROUTING

FreeBSD gw.gensokyo.fujibayashi.jp 8.0-STABLE FreeBSD 8.0-STABLE #1
r200287: Tue May  4 13:33:08 MSD 2010    
root_at_gw.gensokyo.fujibayashi.jp:/usr/obj/usr/src/sys/Eientei  amd64

Some of core.txt contents follow:

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x10
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff806c866f
stack pointer           = 0x28:0xffffff80698d9840
frame pointer           = 0x28:0xffffff80698d98c0
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 1634 (xorp_fea)
trap number             = 12
panic: page fault
cpuid = 0
Uptime: 10m22s

(kgdb) #0  doadump () at pcpu.h:223
#1  0xffffffff805c24f9 in boot (howto=260)
    at /usr/src/sys/kern/kern_shutdown.c:416
#2  0xffffffff805c292c in panic (fmt=0xffffffff80973cac "%s")
    at /usr/src/sys/kern/kern_shutdown.c:579
#3  0xffffffff808ab298 in trap_fatal (frame=0xffffff0082149720,
eva=Variable "eva" is not available.
)
    at /usr/src/sys/amd64/amd64/trap.c:857
#4  0xffffffff808ab664 in trap_pfault (frame=0xffffff80698d9790, usermode=0)
    at /usr/src/sys/amd64/amd64/trap.c:773
#5  0xffffffff808abfe2 in trap (frame=0xffffff80698d9790)
    at /usr/src/sys/amd64/amd64/trap.c:499
#6  0xffffffff808921c3 in calltrap ()
    at /usr/src/sys/amd64/amd64/exception.S:224
#7  0xffffffff806c866f in ip_mdq (m=0x0, ifp=0xffffff0001de62b0,
    rt=0xffffff0001de6200, xmt_vif=65535)
    at /usr/src/sys/netinet/ip_mroute.c:1471
#8  0xffffffff806caf67 in X_ip_mrouter_set (so=Variable "so" is not
available.
)
    at /usr/src/sys/netinet/ip_mroute.c:1093
#9  0xffffffff806cf03a in rip_ctloutput (so=0xffffff00c15de2a8,
    sopt=0xffffff80698d9ad0) at /usr/src/sys/netinet/raw_ip.c:662
#10 0xffffffff80621132 in sosetopt (so=0xffffff00c15de2a8,
    sopt=0xffffff80698d9ad0) at /usr/src/sys/kern/uipc_socket.c:2379
#11 0xffffffff806279f0 in kern_setsockopt (td=0xffffff0082149720, s=33,
level=Variable "level" is not available.

) at /usr/src/sys/kern/uipc_syscalls.c:1331
#12 0xffffffff80627a62 in setsockopt (td=Variable "td" is not available.
)
    at /usr/src/sys/kern/uipc_syscalls.c:1286
#13 0xffffffff808ab8d6 in syscall (frame=0xffffff80698d9c80)
    at /usr/src/sys/amd64/amd64/trap.c:989
#14 0xffffffff808924a1 in Xfast_syscall ()
    at /usr/src/sys/amd64/amd64/exception.S:373
#15 0x000000080144232c in ?? ()
Previous frame inner to this frame (corrupt stack?)

-- 
Kamigishi Rei
KREI-RIPE