network crash in nhop_free

Not sure if I'll be able to get more out of this arm64 machine.
I was playing with ppp and switching routes between LAN and ppp when the crash 
happened.
The system is 2-3 weeks old 14.0-CURRENT as of c8250c5ada85fec.


Tracing pid 0 tid 100014 td 0xffffa00000c00000
db_trace_self() at db_trace_self
db_stack_trace() at db_stack_trace+0x11c
db_command() at db_command+0x244
db_command_loop() at db_command_loop+0x54
db_trap() at db_trap+0xf8
kdb_trap() at kdb_trap+0x1c4
handle_el1h_sync() at handle_el1h_sync+0x74
--- exception, esr 0xf2000000
kdb_enter() at kdb_enter+0x44
vpanic() at vpanic+0x1c4
panic() at panic+0x44
align_abort() at align_abort+0xb8
handle_el1h_sync() at handle_el1h_sync+0x74
--- exception, esr 0x96000021
nhop_free() at nhop_free+0x100
destroy_nhgrp() at destroy_nhgrp+0x38
epoch_call_task() at epoch_call_task+0x158
gtaskqueue_run_locked() at gtaskqueue_run_locked+0x178
gtaskqueue_thread_loop() at gtaskqueue_thread_loop+0x9c
fork_exit() at fork_exit+0x74
fork_trampoline() at fork_trampoline+0x14
-- 
Andriy Gapon