Panic upon usb mouse detach and reattaching

[Rumko <rumcic@xxxxxxxxx>]

After several detaches and reattaches, the machine paniced with "Fatal trap 12:
page fault while in kernel mode"

The core dump is available at leaf:~rumko/crash/ums/*.0

#0  _get_mycpu (di=0xc04ff620) at ./machine/thread.h:83
#1  md_dumpsys (di=0xc04ff620)
at /usr/src/sys/platform/pc32/i386/dump_machdep.c:263
#2  0xc01e46cd in dumpsys () at /usr/src/sys/kern/kern_shutdown.c:880
#3  0xc01e4c8d in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:387
#4  0xc01e4f56 in panic (fmt=0xc0443534 "%s")
at /usr/src/sys/kern/kern_shutdown.c:786
#5  0xc040ffcb in trap_fatal (frame=0xea434808, eva=<value optimized out>)
at /usr/src/sys/platform/pc32/i386/trap.c:1117
#6  0xc04100d9 in trap_pfault (frame=0xea434808, usermode=0, eva=12)
at /usr/src/sys/platform/pc32/i386/trap.c:1018
#7  0xc0410b44 in trap (frame=0xea434808)
at /usr/src/sys/platform/pc32/i386/trap.c:699
#8  0xc03fcf17 in calltrap ()
at /usr/src/sys/platform/pc32/i386/exception.s:785
#9  0xc01d0854 in knote_remove (klist=0xd4292224, kn=0xea366ea0)
at /usr/src/sys/kern/kern_event.c:1370
#10 0xc0312c44 in devfs_detached_filter_detach (kn=0xea366ea0)
at /usr/src/sys/vfs/devfs/devfs_core.c:2234
#11 0xc01d0de7 in knote_detach_and_drop (kn=0xea366ea0)
at /usr/src/sys/kern/kern_event.c:1258
#12 0xc01d157b in kqueue_register (kq=0xea3965b4, kev=0xea4348b8)
at /usr/src/sys/kern/kern_event.c:933
#13 0xc020b2f3 in poll_copyout (arg=0xea434c9c, kevp=0xea4349b4, count=2,
res=0xea434cf0) at /usr/src/sys/kern/sys_generic.c:1325
#14 0xc01d20c5 in kern_kevent (kq=0xea3965b4, nevents=2147483647,
res=0xea434cf0, uap=0xea434c9c, kevent_copyinfn=0xc020b4a5 <poll_copyin>,
    kevent_copyoutfn=0xc020b290 <poll_copyout>, tsp_in=0xea434cb0)
at /usr/src/sys/kern/kern_event.c:697
#15 0xc020b031 in dopoll (uap=0xea434cf0)
at /usr/src/sys/kern/sys_generic.c:1474
#16 sys_poll (uap=0xea434cf0) at /usr/src/sys/kern/sys_generic.c:1228
#17 0xc04113d2 in syscall2 (frame=0xea434d40)
at /usr/src/sys/platform/pc32/i386/trap.c:1310
#18 0xc03fcfc6 in Xint0x80_syscall ()
at /usr/src/sys/platform/pc32/i386/exception.s:876
#19 0x0000001f in ?? ()
-- 
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Regards,
Rumko