bond8 (unregistering): Released all slaves
bond0 (unregistering): Released all slaves
WARNING: CPU: 0 PID: 19931 at net/core/dev.c:8040 rollback_registered_many+0xeca/0x1250 net/core/dev.c:8040
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 19931 Comm: kworker/u4:0 Not tainted 4.20.0-rc3+ #315
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 panic+0x2ad/0x55c kernel/panic.c:188
 __warn.cold.8+0x20/0x45 kernel/panic.c:540
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969
RIP: 0010:rollback_registered_many+0xeca/0x1250 net/core/dev.c:8040
Code: 69 19 00 00 48 c7 c6 e0 ed bc 88 48 c7 c7 20 ee bc 88 c6 05 f0 d9 e1 03 01 e8 d2 e9 17 fb 0f 0b e9 a6 f9 ff ff e8 66 89 4e fb <0f> 0b e9 7b f9 ff ff e8 5a 89 4e fb 0f 0b e9 ea f9 ff ff e8 4e 89
RSP: 0018:ffff888196cbf058 EFLAGS: 00010293
RAX: ffff8881b8ad2040 RBX: ffff8881b2c5c500 RCX: ffffffff8630faf3
RDX: 0000000000000000 RSI: ffffffff8631017a RDI: 0000000000000001
RBP: ffff888196cbf2a0 R08: ffff8881b8ad2040 R09: fffffbfff13e1b98
R10: fffffbfff13e1b98 R11: ffffffff89f0dcc7 R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff84952120 R15: ffff888196cbf138
 unregister_netdevice_many+0xfa/0x4c0 net/core/dev.c:9125
 default_device_exit_batch+0x43a/0x540 net/core/dev.c:9594
 ops_exit_list.isra.5+0x105/0x160 net/core/net_namespace.c:156
 cleanup_net+0x555/0xb10 net/core/net_namespace.c:551
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..