======================================
| [ 88.494288][ T680] #0: ffffffff961e7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3521)
| [ 88.494558][ T680] #1: ffffffff961d6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   88.494858][  T680]
| [   88.494858][  T680] stack backtrace:
[   88.495258][  T680] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   88.495449][  T680] Call Trace:
[   88.495565][  T680]  <TASK>
[ 88.495642][ T680] dump_stack_lvl (lib/dump_stack.c:123)
[ 88.495794][ T680] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 88.495948][ T680] validate_chain (kernel/locking/lockdep.c:3894)
[ 88.496097][ T680] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 88.496246][ T680] ? 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)
[ 88.496391][ T680] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 88.496511][ T680] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 88.496662][ T680] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 88.496811][ T680] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 88.496996][ T680] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[ 88.497204][ T680] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 88.497349][ T680] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 88.497495][ T680] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 88.497647][ T680] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 88.497830][ T680] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 88.497942][ T680] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 88.498127][ T680] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 88.498274][ T680] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 88.498420][ T680] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 88.498565][ T680] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 88.498760][ T680] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 88.498919][ T680] __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))
[ 88.499087][ T680] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 88.499270][ T680] ? __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)
[ 88.499416][ T680] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[ 88.499600][ T680] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 88.499757][ T680] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 88.499903][ T680] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 88.500083][ T680] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 88.500232][ T680] ? 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)
[ 88.500381][ T680] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 88.500527][ T680] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 88.500708][ T680] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[ 88.500866][ T680] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 88.501014][ T680] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 88.501160][ T680] unregister_netdevice_many_notify (net/core/dev.c:11575)
[ 88.501343][ T680] ? 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)
[ 88.501489][ T680] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 88.501602][ T680] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[ 88.501784][ T680] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 88.501977][ T680] ? kfree (mm/slub.c:4613 mm/slub.c:4761)
[ 88.502091][ T680] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[ 88.502240][ T680] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[ 88.502388][ T680] rtnl_dellink (net/core/rtnetlink.c:3487 net/core/rtnetlink.c:3527)
[ 88.502548][ T680] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[ 88.502709][ T680] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 88.502859][ T680] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 88.503007][ T680] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[ 88.503158][ T680] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 88.503306][ T680] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 88.503455][ T680] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[ 88.503619][ T680] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[ 88.503774][ T680] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[ 88.503920][ T680] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 88.504068][ T680] ? 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)
[ 88.504221][ T680] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 88.504345][ T680] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 88.504501][ T680] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 88.504681][ T680] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 88.504831][ T680] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 88.504981][ T680] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 88.505138][ T680] ? 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)
[ 88.505299][ T680] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 88.505456][ T680] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 88.505611][ T680] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 88.505764][ T680] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 88.505909][ T680] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 88.506065][ T680] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 88.506218][ T680] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 88.506398][ T680] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 88.506600][ T680] ___sys_sendmsg (net/socket.c:2650)
[ 88.506744][ T680] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 88.506893][ T680] ? kasan_save_stack (mm/kasan/common.c:49)
[ 88.507073][ T680] ? kasan_save_stack (mm/kasan/common.c:48)
[ 88.507218][ T680] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 88.507365][ T680] ? __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)
[ 88.507557][ T680] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 88.507703][ T680] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 88.507849][ T680] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 88.508033][ T680] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 88.508187][ T680] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 88.508334][ T680] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 88.508481][ T680] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 88.508631][ T680] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 88.508827][ T680] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 88.509041][ T680] __sys_sendmsg (net/socket.c:2680)
[ 88.509269][ T680] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 88.509467][ T680] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 88.509792][ T680] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 88.510025][ T680] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   88.510306][  T680] RIP: 0033:0x7fb2b3b6f9a7
[ 88.510540][ T680] 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)
[   88.511381][  T680] RSP: 002b:00007ffc8cc90e78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   88.511731][  T680] RAX: ffffffffffffffda RBX: 00007ffc8cc915a0 RCX: 00007fb2b3b6f9a7
[   88.512086][  T680] RDX: 0000000000000000 RSI: 00007ffc8cc90ee0 RDI: 0000000000000005
[   88.512450][  T680] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[   88.512810][  T680] R10: 00007fb2b3a2def8 R11: 0000000000000246 R12: 0000000000000002


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