======================================
| [ 50.209790][ T639] #0: ffffffff911e7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [ 50.210064][ T639] #1: ffffffff911d6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   50.210364][  T639]
| [   50.210364][  T639] stack backtrace:
[   50.210771][  T639] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   50.210956][  T639] Call Trace:
[   50.211068][  T639]  <TASK>
[ 50.211148][ T639] dump_stack_lvl (lib/dump_stack.c:123)
[ 50.211305][ T639] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 50.211456][ T639] validate_chain (kernel/locking/lockdep.c:3894)
[ 50.211611][ T639] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 50.211785][ T639] ? 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)
[ 50.211937][ T639] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 50.212052][ T639] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 50.212204][ T639] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 50.212351][ T639] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 50.212544][ T639] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[ 50.212738][ T639] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 50.212883][ T639] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 50.213029][ T639] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 50.213179][ T639] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 50.213360][ T639] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 50.213474][ T639] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 50.213662][ T639] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 50.213808][ T639] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 50.213954][ T639] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 50.214101][ T639] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 50.214248][ T639] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 50.214396][ T639] __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))
[ 50.214545][ T639] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 50.214732][ T639] ? __mutex_unlock_slowpath (./arch/x86/include/asm/atomic64_64.h:101 ./include/linux/atomic/atomic-arch-fallback.h:4329 ./include/linux/atomic/atomic-long.h:1506 ./include/linux/atomic/atomic-instrumented.h:4481 kernel/locking/mutex.c:913)
[ 50.214880][ T639] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[ 50.215062][ T639] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 50.215209][ T639] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 50.215356][ T639] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 50.215538][ T639] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 50.215698][ T639] ? 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)
[ 50.215851][ T639] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 50.215999][ T639] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 50.216180][ T639] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[ 50.216332][ T639] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 50.216479][ T639] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 50.216628][ T639] unregister_netdevice_many_notify (net/core/dev.c:11571)
[ 50.216814][ T639] ? 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)
[ 50.216964][ T639] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 50.217078][ T639] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[ 50.217261][ T639] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 50.217448][ T639] ? kfree (mm/slub.c:4613 mm/slub.c:4761)
[ 50.217563][ T639] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[ 50.217712][ T639] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[ 50.217866][ T639] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[ 50.218018][ T639] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 50.218177][ T639] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 50.218325][ T639] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 50.218470][ T639] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 50.218618][ T639] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 50.218763][ T639] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 50.218911][ T639] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 50.219060][ T639] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 50.219206][ T639] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 50.219352][ T639] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 50.219498][ T639] ? 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)
[ 50.219646][ T639] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 50.219758][ T639] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 50.219904][ T639] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 50.220053][ T639] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 50.220201][ T639] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 50.220352][ T639] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 50.220500][ T639] ? 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)
[ 50.220647][ T639] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 50.220793][ T639] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 50.220939][ T639] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 50.221088][ T639] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 50.221236][ T639] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 50.221385][ T639] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 50.221534][ T639] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 50.221679][ T639] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 50.221865][ T639] ___sys_sendmsg (net/socket.c:2650)
[ 50.222013][ T639] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 50.222161][ T639] ? kasan_save_stack (mm/kasan/common.c:49)
[ 50.222312][ T639] ? kasan_save_stack (mm/kasan/common.c:48)
[ 50.222456][ T639] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 50.222606][ T639] ? __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)
[ 50.222790][ T639] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 50.222936][ T639] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 50.223084][ T639] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 50.223270][ T639] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 50.223421][ T639] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 50.223569][ T639] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 50.223717][ T639] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 50.223867][ T639] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 50.224014][ T639] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 50.224166][ T639] __sys_sendmsg (net/socket.c:2680)
[ 50.224312][ T639] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 50.224461][ T639] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 50.224648][ T639] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 50.224798][ T639] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   50.224988][  T639] RIP: 0033:0x7f25387b69a7
[ 50.225143][ T639] 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)
[   50.225665][  T639] RSP: 002b:00007fff445d1288 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   50.225891][  T639] RAX: ffffffffffffffda RBX: 00007fff445d19b0 RCX: 00007f25387b69a7
[   50.226116][  T639] RDX: 0000000000000000 RSI: 00007fff445d12f0 RDI: 0000000000000005
[   50.226347][  T639] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[   50.226583][  T639] R10: 00007f2538674ef8 R11: 0000000000000246 R12: 0000000000000002


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