======================================
| [ 276.467720][ T3907] #0: ffffffff8a207e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [ 276.467980][ T3907] #1: ffffffff8a1f6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  276.468265][ T3907]
| [  276.468265][ T3907] stack backtrace:
[  276.468661][ T3907] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  276.468839][ T3907] Call Trace:
[  276.468948][ T3907]  <TASK>
[ 276.469024][ T3907] dump_stack_lvl (lib/dump_stack.c:123)
[ 276.469170][ T3907] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 276.469316][ T3907] validate_chain (kernel/locking/lockdep.c:3894)
[ 276.469461][ T3907] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 276.469612][ T3907] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228)
[ 276.469754][ T3907] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 276.469862][ T3907] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 276.470006][ T3907] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 276.470149][ T3907] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 276.470325][ T3907] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 276.470466][ T3907] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 276.470606][ T3907] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 276.470751][ T3907] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 276.470899][ T3907] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 276.471082][ T3907] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 276.471191][ T3907] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 276.471367][ T3907] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 276.471509][ T3907] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 276.471654][ T3907] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 276.471801][ T3907] __netdev_upper_dev_unlink (net/core/dev.c:8000 (discriminator 11) net/core/dev.c:8017 (discriminator 11) net/core/dev.c:8167 (discriminator 11))
[ 276.471945][ T3907] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 276.472088][ T3907] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 276.472273][ T3907] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 276.472451][ T3907] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 276.472596][ T3907] ? __pfx___try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 276.472775][ T3907] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 276.472918][ T3907] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 276.473060][ T3907] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 276.473237][ T3907] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3189 kernel/locking/mutex.h:47 kernel/locking/mutex.c:66)
[ 276.473378][ T3907] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 276.473518][ T3907] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 276.473695][ T3907] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804)
[ 276.473836][ T3907] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 276.473985][ T3907] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 276.474129][ T3907] unregister_netdevice_many_notify (net/core/dev.c:11571)
[ 276.474306][ T3907] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[ 276.474481][ T3907] ? rtnl_dellink (net/core/rtnetlink.c:3512)
[ 276.474622][ T3907] ? sock_def_readable (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/sock.c:3479)
[ 276.474767][ T3907] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 276.474912][ T3907] ? unregister_netdevice_queue (net/core/dev.c:11497)
[ 276.475086][ T3907] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 276.475262][ T3907] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 276.475441][ T3907] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[ 276.475582][ T3907] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 276.475739][ T3907] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 276.475882][ T3907] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 276.476024][ T3907] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 276.476167][ T3907] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 276.476310][ T3907] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 276.476457][ T3907] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 276.476598][ T3907] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 276.476741][ T3907] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 276.476881][ T3907] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 276.477028][ T3907] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228)
[ 276.477174][ T3907] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 276.477283][ T3907] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 276.477427][ T3907] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 276.477571][ T3907] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 276.477713][ T3907] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 276.477858][ T3907] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 276.478002][ T3907] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/net/netns/generic.h:48 net/netlink/af_netlink.c:333)
[ 276.478148][ T3907] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 276.478291][ T3907] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 276.478433][ T3907] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 276.478576][ T3907] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 276.478721][ T3907] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 276.478867][ T3907] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 276.479010][ T3907] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 276.479157][ T3907] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 276.479338][ T3907] ___sys_sendmsg (net/socket.c:2650)
[ 276.479482][ T3907] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 276.479628][ T3907] ? kasan_save_stack (mm/kasan/common.c:49)
[ 276.479772][ T3907] ? kasan_save_stack (mm/kasan/common.c:48)
[ 276.479914][ T3907] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 276.480056][ T3907] ? __call_rcu_common.constprop.0 (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:123 kernel/rcu/tree.c:3087)
[ 276.480237][ T3907] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 276.480382][ T3907] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 276.480527][ T3907] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 276.480700][ T3907] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 276.480843][ T3907] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 276.480984][ T3907] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 276.481127][ T3907] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 276.481274][ T3907] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 276.481416][ T3907] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 276.481560][ T3907] __sys_sendmsg (net/socket.c:2680)
[ 276.481705][ T3907] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 276.481846][ T3907] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 276.482028][ T3907] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 276.482177][ T3907] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  276.482358][ T3907] RIP: 0033:0x7ff1fdad59a7
[ 276.482507][ T3907] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
All code
========
   0:	0a 00                	or     (%rax),%al
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b9                	jmp    0xffffffffffffffc9
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 2e 00 00 00       	mov    $0x2e,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  3b:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  11:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)
[  276.483010][ T3907] RSP: 002b:00007ffd892b9ac8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  276.483225][ T3907] RAX: ffffffffffffffda RBX: 00007ffd892ba1f0 RCX: 00007ff1fdad59a7
[  276.483445][ T3907] RDX: 0000000000000000 RSI: 00007ffd892b9b30 RDI: 0000000000000005
[  276.483656][ T3907] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[  276.483867][ T3907] R10: 00007ff1fd993ef8 R11: 0000000000000246 R12: 0000000000000002


Finger prints:
print_deadlock_bug:validate_chain:__lock_acquire:down_read:blocking_notifier_call_chain