DragonFlyBSD

I got the following panic on my laptop running a latest master:
DragonFly rama 2.9-DEVELOPMENT DragonFly v2.9.1.1083.g90d6d7-DEVELOPMENT #35: Sun Apr 10 21:13:25 HST 2011 root@rama:/usr/obj/usr/src/sys/RAMA i386

panic: overflowed mbuf 0xd8e82800
(kgdb) bt
#0 _get_mycpu (di=0xc072e780) at ./machine/thread.h:79
#1 md_dumpsys (di=0xc072e780) at /usr/src/sys/platform/pc32/i386/dump_machdep.c:264
#2 0xc01bbf28 in dumpsys () at /usr/src/sys/kern/kern_shutdown.c:893
#3 0xc01bc535 in boot (howto=<value optimized out>) at /usr/src/sys/kern/kern_shutdown.c:388
#4 0xc01bc79a in panic (fmt=0xc044d0ec "overflowed mbuf %p") at /usr/src/sys/kern/kern_shutdown.c:799
#5 0xc01fb29c in m_free (m=0xd8e82800) at /usr/src/sys/kern/uipc_mbuf.c:1061
#6 0xc01fb5e7 in m_freem (m=0x0) at /usr/src/sys/kern/uipc_mbuf.c:1225
#7 0xc02808be in sta_input (ni=0xd9400048, m=0xd8e82800, rssi=9, nf=-95) at /usr/src/sys/netproto/802_11/wlan/ieee80211_sta.c:904
#8 0xc0264a92 in ieee80211_input_all (ic=0xd941a048, m=0x0, rssi=9, nf=-95) at /usr/src/sys/netproto/802_11/wlan/ieee80211_input.c:99
#9 0xc0178f79 in iwn_rx_done (sc=0xd92e4000) at /usr/src/sys/dev/netif/iwn/if_iwn.c:2185
#10 iwn_notif_intr (sc=0xd92e4000) at /usr/src/sys/dev/netif/iwn/if_iwn.c:2496
#11 0xc017a1c9 in iwn_intr (arg=0xd92e4000) at /usr/src/sys/dev/netif/iwn/if_iwn.c:2795
#12 0xc01cb496 in lwkt_serialize_handler_call (s=0xc075b80c, func=0xc0179ccc <iwn_intr>, arg=0xd92e4000, frame=0x0) at /usr/src/sys/kern/lwkt_serialize.c:229
#13 0xc01967d2 in ithread_handler (arg=0x11) at /usr/src/sys/kern/kern_intr.c:823
#14 0xc01c6741 in lwkt_deschedule_self (td=Cannot access memory at address 0x8
) at /usr/src/sys/kern/lwkt_thread.c:283
Backtrace stopped: previous frame inner to this frame (corrupt stack?)

kernel and vmcore are available:
http://www.theshell.com/~pavalos/crash/crash15.tar.xz

--Peter