------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(class_idx > MAX_LOCKDEP_KEYS)
WARNING: CPU: 0 PID: 8945 at kernel/locking/lockdep.c:3765 __lock_acquire+0x17b5/0x5490 kernel/locking/lockdep.c:3765
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8945 Comm: kworker/u4:5 Not tainted 5.2.0-rc1+ #4
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+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x2cb/0x744 kernel/panic.c:219
 __warn.cold+0x20/0x4d kernel/panic.c:576
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
RIP: 0010:__lock_acquire+0x17b5/0x5490 kernel/locking/lockdep.c:3765
Code: d2 0f 85 c7 2c 00 00 44 8b 3d 27 a8 29 08 45 85 ff 0f 85 57 f3 ff ff 48 c7 c6 20 c1 6b 87 48 c7 c7 00 98 6b 87 e8 09 d5 eb ff <0f> 0b e9 40 f3 ff ff 0f 0b e9 83 f1 ff ff 8b 0d 47 98 0e 09 85 c9
RSP: 0018:ffff8880660776a0 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815ac7e6 RDI: ffffed100cc0eec6
RBP: ffff888066077848 R08: ffff8880660646c0 R09: fffffbfff11730e9
R10: fffffbfff11730e8 R11: ffffffff88b98743 R12: 0000000075087609
R13: 0000000000000000 R14: 00000000000c1609 R15: 0000000000000000
 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4303
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167
 spin_lock_irq include/linux/spinlock.h:363 [inline]
 flush_workqueue_prep_pwqs+0x1c5/0x590 kernel/workqueue.c:2729
 flush_workqueue+0x54b/0x14c0 kernel/workqueue.c:2800
 rxrpc_destroy_all_connections+0x103/0x487 net/rxrpc/conn_object.c:472
 rxrpc_exit_net+0x1c2/0x310 net/rxrpc/net_ns.c:126
 ops_exit_list.isra.0+0xaa/0x150 net/core/net_namespace.c:154
 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:553
 process_one_work+0x989/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x354/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..