======================================
| [ 29.234916][ T439] #0: ffffffffa3de7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3521)
| [ 29.235346][ T439] #1: ffffffffa3dd6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   29.235863][  T439]
| [   29.235863][  T439] stack backtrace:
[   29.236483][  T439] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   29.236752][  T439] Call Trace:
[   29.236915][  T439]  <TASK>
[ 29.237028][ T439] dump_stack_lvl (lib/dump_stack.c:123)
[ 29.237246][ T439] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 29.237463][ T439] validate_chain (kernel/locking/lockdep.c:3894)
[ 29.237680][ T439] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 29.237895][ T439] ? 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)
[ 29.238111][ T439] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 29.238290][ T439] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 29.238509][ T439] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 29.238723][ T439] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 29.238991][ T439] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[ 29.239260][ T439] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 29.239475][ T439] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 29.239696][ T439] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 29.239923][ T439] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 29.240209][ T439] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 29.240383][ T439] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 29.240666][ T439] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 29.240892][ T439] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 29.241114][ T439] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 29.241335][ T439] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 29.241558][ T439] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 29.241777][ T439] __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))
[ 29.241997][ T439] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 29.242255][ T439] ? __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)
[ 29.242468][ T439] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[ 29.242749][ T439] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 29.242978][ T439] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 29.243192][ T439] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 29.243463][ T439] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 29.243699][ T439] ? 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)
[ 29.243931][ T439] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 29.244165][ T439] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 29.244445][ T439] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[ 29.244692][ T439] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 29.244911][ T439] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 29.245136][ T439] unregister_netdevice_many_notify (net/core/dev.c:11575)
[ 29.245401][ T439] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 29.245622][ T439] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[ 29.245901][ T439] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 29.246114][ T439] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 29.246359][ T439] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 29.246582][ T439] ? unregister_netdevice_queue (net/core/dev.c:11501)
[ 29.246861][ T439] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11500)
[ 29.247140][ T439] ? net_generic (./include/net/netns/generic.h:51)
[ 29.247373][ T439] rtnl_dellink (net/core/rtnetlink.c:3487 net/core/rtnetlink.c:3527)
[ 29.247603][ T439] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[ 29.247857][ T439] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 29.248099][ T439] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 29.248333][ T439] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[ 29.248567][ T439] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 29.248800][ T439] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 29.249036][ T439] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[ 29.249265][ T439] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[ 29.249493][ T439] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[ 29.249730][ T439] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 29.249956][ T439] ? 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)
[ 29.250186][ T439] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 29.250360][ T439] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 29.250587][ T439] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 29.250814][ T439] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 29.251029][ T439] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 29.251268][ T439] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 29.251502][ T439] ? 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)
[ 29.251737][ T439] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 29.251980][ T439] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 29.252219][ T439] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 29.252458][ T439] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 29.252687][ T439] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 29.252928][ T439] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 29.253164][ T439] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 29.253394][ T439] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 29.253687][ T439] ___sys_sendmsg (net/socket.c:2650)
[ 29.253867][ T439] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 29.254015][ T439] ? kasan_save_stack (mm/kasan/common.c:49)
[ 29.254164][ T439] ? kasan_save_stack (mm/kasan/common.c:48)
[ 29.254366][ T439] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 29.254534][ T439] ? __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)
[ 29.254732][ T439] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 29.254927][ T439] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 29.255090][ T439] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 29.255284][ T439] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 29.255476][ T439] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 29.255642][ T439] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 29.255795][ T439] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 29.255942][ T439] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 29.256087][ T439] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 29.256235][ T439] __sys_sendmsg (net/socket.c:2680)
[ 29.256384][ T439] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 29.256529][ T439] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 29.256729][ T439] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 29.256881][ T439] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   29.257063][  T439] RIP: 0033:0x7fd35951a9a7
[ 29.257216][ T439] 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)
[   29.257792][  T439] RSP: 002b:00007fff535fc4a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   29.258018][  T439] RAX: ffffffffffffffda RBX: 00007fff535fcbd0 RCX: 00007fd35951a9a7
[   29.258268][  T439] RDX: 0000000000000000 RSI: 00007fff535fc510 RDI: 0000000000000005
[   29.258512][  T439] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[   29.258745][  T439] R10: 00007fd3593d8ef8 R11: 0000000000000246 R12: 0000000000000002


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