------------[ cut here ]------------
lockdep bfs error:-1
WARNING: CPU: 1 PID: 132 at kernel/locking/lockdep.c:1960 print_bfs_bug+0x130/0x1e0 kernel/locking/lockdep.c:1960
Modules linked in:
CPU: 1 PID: 132 Comm: kworker/u4:3 Not tainted 5.9.0-rc7-next-20200930-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:print_bfs_bug+0x130/0x1e0 kernel/locking/lockdep.c:1960
Code: e2 08 00 74 2c 48 c7 c7 c0 7f a6 8d e8 49 51 01 00 66 90 85 db 75 05 5b 5d 41 5c c3 89 ee 48 c7 c7 20 e8 ab 88 e8 7b e5 c0 06 <0f> 0b 5b 5d 41 5c c3 0f 0b e8 62 82 e9 06 85 c0 74 d7 48 c7 c0 38
RSP: 0018:ffffc900013f6ef0 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff8880a8ebc480 RSI: ffffffff815df1a5 RDI: fffff5200027edd0
RBP: 00000000ffffffff R08: 0000000000000001 R09: ffff8880ae520f8b
R10: 0000000000000000 R11: 207065646b636f6c R12: ffff8880a8ebc480
R13: dffffc0000000000 R14: 0000000000000008 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004e1f30 CR3: 00000000a6e5e000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 check_irq_usage+0x6b4/0xc60 kernel/locking/lockdep.c:2585
 check_prev_add kernel/locking/lockdep.c:2823 [inline]
 check_prevs_add kernel/locking/lockdep.c:2944 [inline]
 validate_chain kernel/locking/lockdep.c:3562 [inline]
 __lock_acquire+0x2873/0x56d0 kernel/locking/lockdep.c:4796
 lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5398
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
 alloc_object lib/debugobjects.c:239 [inline]
 __debug_object_init+0x5c6/0xd10 lib/debugobjects.c:548
 debug_object_init lib/debugobjects.c:595 [inline]
 debug_object_activate+0x32c/0x3e0 lib/debugobjects.c:681
 debug_rcu_head_queue kernel/rcu/rcu.h:176 [inline]
 kvfree_call_rcu+0x32/0xb10 kernel/rcu/tree.c:3432
 __hw_addr_del_entry+0x2dd/0x3b0 net/core/dev_addr_lists.c:107
 __hw_addr_del_ex+0x129/0x150 net/core/dev_addr_lists.c:121
 __dev_mc_del net/core/dev_addr_lists.c:815 [inline]
 dev_mc_del+0xb9/0x110 net/core/dev_addr_lists.c:833
 igmp6_group_dropped+0x2fd/0xbd0 net/ipv6/mcast.c:705
 ipv6_mc_down+0x5c/0x280 net/ipv6/mcast.c:2538
 ipv6_mc_destroy_dev+0x1e/0x2f0 net/ipv6/mcast.c:2600
 addrconf_ifdown.isra.0+0xf36/0x1590 net/ipv6/addrconf.c:3836
 addrconf_notify+0x55c/0x2310 net/ipv6/addrconf.c:3627
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2034
 call_netdevice_notifiers_extack net/core/dev.c:2046 [inline]
 call_netdevice_notifiers net/core/dev.c:2060 [inline]
 rollback_registered_many+0x97f/0x1550 net/core/dev.c:9409
 unregister_netdevice_many.part.0+0x1a/0x2f0 net/core/dev.c:10579
 unregister_netdevice_many+0x36/0x50 net/core/dev.c:10578
 ip_tunnel_delete_nets+0x3eb/0x5b0 net/ipv4/ip_tunnel.c:1125
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:189
 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:603
 process_one_work+0x933/0x15a0 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296