======================================
| [ 651.427358][ T4549] #0: ffffffffa1807e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3521)
| [ 651.427647][ T4549] #1: ffffffffa17f6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  651.427937][ T4549]
| [  651.427937][ T4549] stack backtrace:
[  651.428334][ T4549] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  651.428523][ T4549] Call Trace:
[  651.428635][ T4549]  <TASK>
[ 651.428711][ T4549] dump_stack_lvl (lib/dump_stack.c:123)
[ 651.428862][ T4549] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 651.429011][ T4549] validate_chain (kernel/locking/lockdep.c:3894)
[ 651.429157][ T4549] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 651.429305][ T4549] ? 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)
[ 651.429448][ T4549] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 651.429559][ T4549] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 651.429713][ T4549] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 651.429861][ T4549] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 651.430038][ T4549] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 651.430181][ T4549] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 651.430328][ T4549] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 651.430471][ T4549] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 651.430614][ T4549] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 651.430804][ T4549] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 651.430918][ T4549] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 651.431098][ T4549] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 651.431241][ T4549] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 651.431388][ T4549] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 651.431534][ T4549] __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))
[ 651.431681][ T4549] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 651.431834][ T4549] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 651.432011][ T4549] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 651.432192][ T4549] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 651.432338][ T4549] ? __pfx___try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 651.432519][ T4549] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 651.432672][ T4549] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 651.432814][ T4549] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 651.432999][ T4549] ? 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)
[ 651.433143][ T4549] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 651.433288][ T4549] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 651.433467][ T4549] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804)
[ 651.433614][ T4549] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 651.433763][ T4549] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 651.433908][ T4549] unregister_netdevice_many_notify (net/core/dev.c:11575)
[ 651.434099][ T4549] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[ 651.434275][ T4549] ? rtnl_dellink (net/core/rtnetlink.c:3521)
[ 651.434419][ T4549] ? sock_def_readable (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/sock.c:3479)
[ 651.434564][ T4549] ? __pfx___mutex_lock (kernel/locking/mutex.c:734)
[ 651.434713][ T4549] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 651.434859][ T4549] ? unregister_netdevice_queue (net/core/dev.c:11501)
[ 651.435037][ T4549] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11500)
[ 651.435219][ T4549] ? __nla_validate_parse (./include/net/netlink.h:1270 (discriminator 1) lib/nlattr.c:622 (discriminator 1))
[ 651.435366][ T4549] rtnl_dellink (net/core/rtnetlink.c:3487 net/core/rtnetlink.c:3527)
[ 651.435511][ T4549] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[ 651.435674][ T4549] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 651.435819][ T4549] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 651.435964][ T4549] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[ 651.436109][ T4549] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 651.436259][ T4549] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 651.436404][ T4549] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[ 651.436548][ T4549] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[ 651.436692][ T4549] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[ 651.436835][ T4549] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 651.436978][ T4549] ? 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)
[ 651.437127][ T4549] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 651.437250][ T4549] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 651.437397][ T4549] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 651.437551][ T4549] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 651.437701][ T4549] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 651.437850][ T4549] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 651.437996][ T4549] ? 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)
[ 651.438139][ T4549] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 651.438288][ T4549] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 651.438435][ T4549] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 651.438584][ T4549] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 651.438729][ T4549] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 651.438881][ T4549] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 651.439032][ T4549] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 651.439181][ T4549] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 651.439375][ T4549] ___sys_sendmsg (net/socket.c:2650)
[ 651.439520][ T4549] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 651.439667][ T4549] ? kasan_save_stack (mm/kasan/common.c:49)
[ 651.439813][ T4549] ? kasan_save_stack (mm/kasan/common.c:48)
[ 651.439956][ T4549] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 651.440100][ T4549] ? __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)
[ 651.440285][ T4549] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 651.440441][ T4549] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 651.440593][ T4549] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 651.440773][ T4549] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 651.440922][ T4549] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 651.441066][ T4549] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 651.441208][ T4549] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 651.441355][ T4549] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 651.441500][ T4549] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 651.441654][ T4549] __sys_sendmsg (net/socket.c:2680)
[ 651.441797][ T4549] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 651.441940][ T4549] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 651.442129][ T4549] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 651.442273][ T4549] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  651.442450][ T4549] RIP: 0033:0x7f2f6d8df9a7
[ 651.442604][ T4549] 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)
[  651.443117][ T4549] RSP: 002b:00007ffebb805588 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  651.443340][ T4549] RAX: ffffffffffffffda RBX: 00007ffebb805cc0 RCX: 00007f2f6d8df9a7
[  651.443559][ T4549] RDX: 0000000000000000 RSI: 00007ffebb8055f0 RDI: 0000000000000005
[  651.443775][ T4549] RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000078
[  651.443997][ T4549] R10: 00007f2f6d79d4a8 R11: 0000000000000246 R12: 0000000000000001


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