======================================
| [ 540.201195][ T2939] #0: ffffffff9a7e7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [ 540.201460][ T2939] #1: ffffffff9a7d6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  540.201754][ T2939]
| [  540.201754][ T2939] stack backtrace:
[  540.202153][ T2939] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  540.202337][ T2939] Call Trace:
[  540.202448][ T2939]  <TASK>
[ 540.202525][ T2939] dump_stack_lvl (lib/dump_stack.c:123)
[ 540.202675][ T2939] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 540.202825][ T2939] validate_chain (kernel/locking/lockdep.c:3894)
[ 540.202971][ T2939] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 540.203124][ T2939] ? 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)
[ 540.203275][ T2939] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 540.203387][ T2939] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 540.203538][ T2939] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 540.203690][ T2939] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 540.203875][ T2939] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[ 540.204065][ T2939] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 540.204216][ T2939] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 540.204367][ T2939] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 540.204514][ T2939] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 540.204699][ T2939] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 540.204814][ T2939] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 540.204998][ T2939] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 540.205144][ T2939] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 540.205305][ T2939] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 540.205451][ T2939] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 540.205605][ T2939] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 540.205751][ T2939] __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))
[ 540.205901][ T2939] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 540.206085][ T2939] ? __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)
[ 540.206233][ T2939] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[ 540.206416][ T2939] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 540.206564][ T2939] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 540.206713][ T2939] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 540.206894][ T2939] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 540.207047][ T2939] ? 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)
[ 540.207193][ T2939] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 540.207343][ T2939] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 540.207526][ T2939] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[ 540.207678][ T2939] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 540.207826][ T2939] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 540.207973][ T2939] unregister_netdevice_many_notify (net/core/dev.c:11571)
[ 540.208177][ T2939] ? 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)
[ 540.208325][ T2939] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 540.208439][ T2939] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[ 540.208621][ T2939] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 540.208807][ T2939] ? kfree (mm/slub.c:4613 mm/slub.c:4761)
[ 540.208919][ T2939] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[ 540.209071][ T2939] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[ 540.209222][ T2939] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[ 540.209374][ T2939] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 540.209536][ T2939] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 540.209685][ T2939] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 540.209832][ T2939] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 540.209985][ T2939] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 540.210159][ T2939] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 540.210312][ T2939] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 540.210460][ T2939] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 540.210616][ T2939] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 540.210763][ T2939] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 540.210912][ T2939] ? 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)
[ 540.211062][ T2939] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 540.211175][ T2939] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 540.211323][ T2939] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 540.211475][ T2939] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 540.211621][ T2939] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 540.211771][ T2939] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 540.211926][ T2939] ? 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)
[ 540.212076][ T2939] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 540.212223][ T2939] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 540.212374][ T2939] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 540.212526][ T2939] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 540.212672][ T2939] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 540.212821][ T2939] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 540.212968][ T2939] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 540.213120][ T2939] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 540.213304][ T2939] ___sys_sendmsg (net/socket.c:2650)
[ 540.213452][ T2939] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 540.213600][ T2939] ? kasan_save_stack (mm/kasan/common.c:49)
[ 540.213747][ T2939] ? kasan_save_stack (mm/kasan/common.c:48)
[ 540.213891][ T2939] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 540.214042][ T2939] ? __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)
[ 540.214225][ T2939] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 540.214379][ T2939] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 540.214526][ T2939] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 540.214714][ T2939] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 540.214865][ T2939] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 540.215012][ T2939] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 540.215161][ T2939] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 540.215320][ T2939] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 540.215473][ T2939] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 540.215622][ T2939] __sys_sendmsg (net/socket.c:2680)
[ 540.215772][ T2939] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 540.215920][ T2939] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 540.216113][ T2939] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 540.216259][ T2939] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  540.216441][ T2939] RIP: 0033:0x7f3a09c419a7
[ 540.216598][ T2939] 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)
[  540.217118][ T2939] RSP: 002b:00007ffda675a328 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  540.217343][ T2939] RAX: ffffffffffffffda RBX: 00007ffda675aa50 RCX: 00007f3a09c419a7
[  540.217568][ T2939] RDX: 0000000000000000 RSI: 00007ffda675a390 RDI: 0000000000000005
[  540.217798][ T2939] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[  540.218026][ T2939] R10: 00007f3a09affef8 R11: 0000000000000246 R12: 0000000000000002


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