Page not present FBSD mtx_lock vm_page_queue_free_mtx held

Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address   = 0x18
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff80acf3ee
stack pointer           = 0x28:0xffffff810eda6680
frame pointer           = 0x28:0xffffff810eda6760
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         = 2551 (VBoxHeadless)



#1  0xffffffff802f0680 in db_dump (dummy=Variable "dummy" is not available.
)
    at /root/deviant2/sys/ddb/db_command.c:537
#2  0xffffffff802efbe1 in db_command (last_cmdp=0xffffffff8108fec0, cmd_table=Variable "cmd_table" is not available.

) at /root/deviant2/sys/ddb/db_command.c:448
#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=12, code=0, tf=0xffffff810eda65d0)
    at /root/deviant2/sys/kern/subr_kdb.c:625
#6  0xffffffff80ad280d in trap_fatal (frame=0xffffff810eda65d0, eva=Variable "eva" is not available.
)
    at /root/deviant2/sys/amd64/amd64/trap.c:814
#7  0xffffffff80ad2b2b in trap_pfault (frame=0xffffff810eda65d0, usermode=0)
    at /root/deviant2/sys/amd64/amd64/trap.c:735
#8  0xffffffff80ad2f3f in trap (frame=0xffffff810eda65d0)
    at /root/deviant2/sys/amd64/amd64/trap.c:474
#9  0xffffffff80abc98f in calltrap ()
    at /root/deviant2/sys/amd64/amd64/exception.S:228
#10 0xffffffff80acf3ee in pmap_enter (pmap=0xfffffe000684f8d8,
    va=34366734336, access=0 '\0', m=0xfffffe00b2703c60, prot=7 '\a', wired=1)
    at pcpu.h:224
#11 0xffffffff818a4f2f in rtR0MemObjNativeMapUser ()
   from /boot/modules/vboxdrv.ko
#12 0xffffffff818a4080 in RTR0MemObjMapUserTag ()
   from /boot/modules/vboxdrv.ko