netbsd-7 panic

[John Klos <john%ziaspace.com@localhost>]

I have an amd64 machine running netbsd-7 from 6-August-2015 which 
does common hosting (email, web, DNS), IPv6 tunnels and NAT, 
amongst other things. It paniced like this a few weeks ago when it had 
been running netbsd-7 from March, but otherwise it's been problem free.

Any thoughts or ideas about what could be causing this?


fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff80722fb2 cs 8 rflags 10297 cr2 36 ilevel 2 
rsp ff
fffe811cfebec0
curlwp 0xfffffe842df3b860 pid 0.5 lowest kstack 0xfffffe811cfe92c0
panic: trap
cpu0: Begin traceback...
vpanic() at netbsd:vpanic+0x13c
snprintf() at netbsd:snprintf
startlwp() at netbsd:startlwp
alltraps() at netbsd:alltraps+0x96
ipf_frag_delete() at netbsd:ipf_frag_delete+0x74
ipf_frag_expire() at netbsd:ipf_frag_expire+0x152
ipf_slowtimer() at netbsd:ipf_slowtimer+0x15
ipf_timer_func() at netbsd:ipf_timer_func+0x2d
callout_softclock() at netbsd:callout_softclock+0x248
softint_dispatch() at netbsd:softint_dispatch+0x79
DDB lost frame for netbsd:Xsoftintr+0x4f, trying 0xfffffe811cfebff0
Xsoftintr() at netbsd:Xsoftintr+0x4f
--- interrupt ---
0:
cpu0: End traceback...