------------[ cut here ]------------
workqueue: WQ_MEM_RECLAIM hwsim_wq:destroy_radio is flushing !WQ_MEM_RECLAIM events_highpri:flush_backlog
WARNING: CPU: 0 PID: 8126 at kernel/workqueue.c:2439 check_flush_dependency+0x239/0x380 kernel/workqueue.c:2435
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 8126 Comm: kworker/0:4 Not tainted 4.16.0-rc1+ #311
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hwsim_wq destroy_radio
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1dc/0x200 kernel/panic.c:547
 report_bug+0x211/0x2d0 lib/bug.c:184
 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178
 fixup_bug arch/x86/kernel/traps.c:247 [inline]
 do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
 invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:988
RIP: 0010:check_flush_dependency+0x239/0x380 kernel/workqueue.c:2435
RSP: 0018:ffff8801b6296d78 EFLAGS: 00010082
RAX: dffffc0000000008 RBX: ffff8801d33c50c0 RCX: ffffffff815aaf5e
RDX: 0000000000000000 RSI: 1ffff10036c52d5f RDI: 1ffff10036c52d34
RBP: ffff8801b6296da8 R08: 0000000000000000 R09: 1ffff10036c52d06
R10: ffff8801b6296c70 R11: 0000000000000005 R12: ffff8801db014b70
R13: ffffffff843e8ed0 R14: ffff8801d3a74500 R15: 0000000000000000
 start_flush_work kernel/workqueue.c:2827 [inline]
 flush_work+0x2f7/0x8f0 kernel/workqueue.c:2870
 flush_all_backlogs net/core/dev.c:4758 [inline]
 rollback_registered_many+0x672/0xe20 net/core/dev.c:7372
 unregister_netdevice_many.part.119+0x87/0x420 net/core/dev.c:8462
 unregister_netdevice_many+0xbb/0x100 net/core/dev.c:8461
 ieee80211_remove_interfaces+0x4b3/0x9b0 net/mac80211/iface.c:1960
 ieee80211_unregister_hw+0x4c/0x270 net/mac80211/main.c:1184
 mac80211_hwsim_del_radio+0x1ee/0x3b0 drivers/net/wireless/mac80211_hwsim.c:2856
 destroy_radio+0x9d/0x100 drivers/net/wireless/mac80211_hwsim.c:3396
 process_one_work+0xbbf/0x1af0 kernel/workqueue.c:2113
 worker_thread+0x223/0x1990 kernel/workqueue.c:2247
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:429
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..