kern/51755: ether_addmulti() triggers kernel diagnostic assertion "(!cpu_intr_p() && !cpu_softintr_p())" failed

[qfh02545%nifty.com@localhost]

>Number:         51755
>Category:       kern
>Synopsis:       ether_addmulti() triggers kernel diagnostic assertion "(!cpu_intr_p() && !cpu_softintr_p())" failed
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Dec 31 03:00:01 +0000 2016
>Originator:     HITOSHI Osada
>Release:        NetBSD-current 20161231
>Organization:
>Environment:
NetBSD 7.99.53 (LLANO_VMWARE) #0: Sat Dec 31 11:16:57 JST 2016
	that@llano:/tmp/obj/sys/arch/amd64/compile/LLANO_VMWARE

>Description:
-------------------------
panic: kernel diagnostic assertion "(!cpu_intr_p() && !cpu_softintr_p())" failed: file "/Sources/src/sys/kern/subr_kmem.c", line 389 kmem(9) should not be used from the interrupt context
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff80115465 cs 8 rflags 246 cr2 778695c110f8 ilevel 6 rsp fffffe80bff07500
curlwp 0xfffffe813fb3d460 pid 0.3 lowest kstack 0xfffffe80bff042c0
Stopped in pid 0.3 (system) at  netbsd:breakpoint+0x5:  leave
db{0}> bt
breakpoint() at netbsd:breakpoint+0x5
vpanic() at netbsd:vpanic+0x13d
sowwakeup() at netbsd:sowwakeup
kmem_alloc() at netbsd:kmem_alloc+0x3f
ether_addmulti() at netbsd:ether_addmulti+0x33
wm_ioctl() at netbsd:wm_ioctl+0x5a
if_mcast_op() at netbsd:if_mcast_op+0x6a
in6_addmulti() at netbsd:in6_addmulti+0x30c
in6_joingroup() at netbsd:in6_joingroup+0x45
in6_update_ifa1() at netbsd:in6_update_ifa1+0xaff
in6_update_ifa() at netbsd:in6_update_ifa+0x38
in6_tmpifadd() at netbsd:in6_tmpifadd+0x286
nd6_ra_input() at netbsd:nd6_ra_input+0x15b0
icmp6_input() at netbsd:icmp6_input+0x1143
ip6_input() at netbsd:ip6_input+0x618
ip6intr() at netbsd:ip6intr+0x7f
softint_dispatch() at netbsd:softint_dispatch+0xe4
DDB lost frame for netbsd:Xsoftintr+0x4f, trying 0xfffffe80bff07ff0
Xsoftintr() at netbsd:Xsoftintr+0x4f
--- interrupt ---
0:
db{0}> halt
No such command: halt
db{0}> poweroff
No such command: poweroff
db{0}> reboot
rebooting...
-------------------------

>How-To-Repeat:
Unknown(receive IPv6 RA?)

>Fix: