virtualbox panic with FreeBSD CURRENT

Unread portion of the kernel message buffer:
panic: mutex vm page queue free mutex not owned at /root/deviant2/sys/vm/vm_phys
.c:882
cpuid = 3
/var/crash/core.txt.1: unmodified: line 1
#3  0xffffffff802efe30 in db_command_loop ()
    at /root/deviant2/sys/ddb/db_command.c:501
#4  0xffffffff802f2019 in db_trap (type=Variable "type" is not available.
)
    at /root/deviant2/sys/ddb/db_main.c:229
#5  0xffffffff80810dd1 in kdb_trap (type=3, code=0, tf=0xffffff810ee46570)
    at /root/deviant2/sys/kern/subr_kdb.c:625
#6  0xffffffff80ad2d38 in trap (frame=0xffffff810ee46570)
    at /root/deviant2/sys/amd64/amd64/trap.c:591
#7  0xffffffff80abc98f in calltrap ()
    at /root/deviant2/sys/amd64/amd64/exception.S:228
#8  0xffffffff80810b7b in kdb_enter (why=0xffffffff80ce2ef4 "panic",
    msg=0x80 <Address 0x80 out of bounds>) at cpufunc.h:63
#9  0xffffffff807d8f40 in panic (fmt=Variable "fmt" is not available.
)
    at /root/deviant2/sys/kern/kern_shutdown.c:600
#10 0xffffffff807c7e5c in _mtx_assert (m=Variable "m" is not available.
)
    at /root/deviant2/sys/kern/kern_mutex.c:707
#11 0xffffffff80a5016e in vm_phys_alloc_contig (npages=1, low=0,
    high=18446744073709551615, alignment=4096, boundary=0)
    at /root/deviant2/sys/vm/vm_phys.c:882
#12 0xffffffff818a22f1 in rtR0MemObjFreeBSDAllocPhysPages ()
   from /boot/modules/vboxdrv.ko
#13 0xffffffff81889dd3 in SUPR0PageAllocEx () from /boot/modules/vboxdrv.ko