======================================
| [ 142.562305][ T927] #0: ffffffff9cfe7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [ 142.562580][ T927] #1: ffffffff9cfd6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  142.562887][  T927]
| [  142.562887][  T927] stack backtrace:
[  142.563295][  T927] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  142.563483][  T927] Call Trace:
[  142.563635][  T927]  <TASK>
[ 142.563727][ T927] dump_stack_lvl (lib/dump_stack.c:123)
[ 142.563891][ T927] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 142.564045][ T927] validate_chain (kernel/locking/lockdep.c:3894)
[ 142.564207][ T927] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 142.564385][ T927] ? 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)
[ 142.564563][ T927] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 142.564708][ T927] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 142.564862][ T927] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 142.565051][ T927] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 142.565276][ T927] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[ 142.565537][ T927] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 142.565743][ T927] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 142.565967][ T927] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 142.566169][ T927] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 142.566368][ T927] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 142.566484][ T927] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 142.566682][ T927] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 142.566866][ T927] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 142.567046][ T927] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 142.567249][ T927] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 142.567452][ T927] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 142.567660][ T927] __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))
[ 142.567851][ T927] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 142.568038][ T927] ? __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)
[ 142.568198][ T927] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[ 142.568386][ T927] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 142.568540][ T927] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 142.568690][ T927] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 142.568881][ T927] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 142.569040][ T927] ? 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)
[ 142.569233][ T927] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 142.569386][ T927] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 142.569583][ T927] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[ 142.569741][ T927] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 142.569901][ T927] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 142.570087][ T927] unregister_netdevice_many_notify (net/core/dev.c:11571)
[ 142.570325][ T927] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[ 142.570520][ T927] ? rtnl_dellink (net/core/rtnetlink.c:3512)
[ 142.570729][ T927] ? sock_def_readable (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/sock.c:3479)
[ 142.570931][ T927] ? __pfx___mutex_lock (kernel/locking/mutex.c:734)
[ 142.571123][ T927] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 142.571349][ T927] ? unregister_netdevice_queue (net/core/dev.c:11497)
[ 142.571553][ T927] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 142.571781][ T927] ? __nla_validate_parse (./include/net/netlink.h:1270 (discriminator 1) lib/nlattr.c:622 (discriminator 1))
[ 142.571934][ T927] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[ 142.572087][ T927] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 142.572270][ T927] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 142.572484][ T927] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 142.572637][ T927] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 142.572791][ T927] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 142.572986][ T927] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 142.573139][ T927] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 142.573298][ T927] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 142.573450][ T927] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 142.573603][ T927] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 142.573753][ T927] ? 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)
[ 142.573901][ T927] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 142.574023][ T927] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 142.574189][ T927] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 142.574343][ T927] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 142.574492][ T927] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 142.574645][ T927] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 142.574797][ T927] ? 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)
[ 142.574948][ T927] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 142.575107][ T927] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 142.575315][ T927] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 142.575471][ T927] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 142.575622][ T927] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 142.575775][ T927] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 142.575924][ T927] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 142.576075][ T927] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 142.576285][ T927] ___sys_sendmsg (net/socket.c:2650)
[ 142.576435][ T927] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 142.576586][ T927] ? kasan_save_stack (mm/kasan/common.c:49)
[ 142.576738][ T927] ? kasan_save_stack (mm/kasan/common.c:48)
[ 142.576885][ T927] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 142.577035][ T927] ? __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)
[ 142.577234][ T927] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 142.577391][ T927] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 142.577543][ T927] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 142.577733][ T927] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 142.577890][ T927] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 142.578071][ T927] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 142.578266][ T927] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 142.578420][ T927] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 142.578603][ T927] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 142.578766][ T927] __sys_sendmsg (net/socket.c:2680)
[ 142.578917][ T927] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 142.579067][ T927] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 142.579340][ T927] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 142.579504][ T927] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  142.579716][  T927] RIP: 0033:0x7f9889cb59a7
[ 142.579888][ T927] 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)
[  142.580613][  T927] RSP: 002b:00007ffeb10465f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  142.580911][  T927] RAX: ffffffffffffffda RBX: 00007ffeb1046d20 RCX: 00007f9889cb59a7
[  142.581187][  T927] RDX: 0000000000000000 RSI: 00007ffeb1046660 RDI: 0000000000000005
[  142.581414][  T927] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[  142.581642][  T927] R10: 00007f9889b73ef8 R11: 0000000000000246 R12: 0000000000000002


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