======================================
| [ 1284.435554][ T4335] #0: ffffffff8e7e7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [ 1284.435825][ T4335] #1: ffffffff8e7d6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [ 1284.436125][ T4335]
| [ 1284.436125][ T4335] stack backtrace:
[ 1284.436529][ T4335] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1284.436718][ T4335] Call Trace:
[ 1284.436831][ T4335]  <TASK>
[ 1284.436916][ T4335] dump_stack_lvl (lib/dump_stack.c:123)
[ 1284.437077][ T4335] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 1284.437224][ T4335] validate_chain (kernel/locking/lockdep.c:3894)
[ 1284.437388][ T4335] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 1284.437538][ T4335] ? 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)
[ 1284.437683][ T4335] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 1284.437795][ T4335] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 1284.437953][ T4335] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 1284.438098][ T4335] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 1284.438288][ T4335] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[ 1284.438475][ T4335] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 1284.438637][ T4335] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 1284.438788][ T4335] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 1284.438935][ T4335] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 1284.439128][ T4335] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 1284.439251][ T4335] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 1284.439441][ T4335] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 1284.439587][ T4335] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 1284.439733][ T4335] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 1284.439880][ T4335] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 1284.440028][ T4335] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 1284.440176][ T4335] __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))
[ 1284.440329][ T4335] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 1284.440508][ T4335] ? __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)
[ 1284.440669][ T4335] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[ 1284.440854][ T4335] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 1284.441015][ T4335] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 1284.441163][ T4335] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 1284.441349][ T4335] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[ 1284.441512][ T4335] ? 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)
[ 1284.441659][ T4335] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 1284.441808][ T4335] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 1284.441991][ T4335] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[ 1284.442143][ T4335] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 1284.442293][ T4335] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 1284.442443][ T4335] unregister_netdevice_many_notify (net/core/dev.c:11571)
[ 1284.442634][ T4335] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[ 1284.442816][ T4335] ? rtnl_dellink (net/core/rtnetlink.c:3512)
[ 1284.442965][ T4335] ? sock_def_readable (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/sock.c:3479)
[ 1284.443121][ T4335] ? __pfx___mutex_lock (kernel/locking/mutex.c:734)
[ 1284.443284][ T4335] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 1284.443430][ T4335] ? unregister_netdevice_queue (net/core/dev.c:11497)
[ 1284.443621][ T4335] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 1284.443804][ T4335] ? __nla_validate_parse (./include/net/netlink.h:1270 (discriminator 1) lib/nlattr.c:622 (discriminator 1))
[ 1284.443956][ T4335] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[ 1284.444104][ T4335] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 1284.444274][ T4335] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 1284.444422][ T4335] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 1284.444567][ T4335] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 1284.444713][ T4335] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 1284.444866][ T4335] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 1284.445015][ T4335] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 1284.445160][ T4335] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 1284.445306][ T4335] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 1284.445451][ T4335] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 1284.445598][ T4335] ? 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)
[ 1284.445743][ T4335] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 1284.445861][ T4335] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 1284.446023][ T4335] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 1284.446172][ T4335] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 1284.446319][ T4335] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 1284.446470][ T4335] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 1284.446637][ T4335] ? 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)
[ 1284.446784][ T4335] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 1284.446943][ T4335] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 1284.447092][ T4335] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 1284.447248][ T4335] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 1284.447401][ T4335] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 1284.447549][ T4335] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 1284.447696][ T4335] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 1284.447842][ T4335] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 1284.448035][ T4335] ___sys_sendmsg (net/socket.c:2650)
[ 1284.448188][ T4335] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 1284.448336][ T4335] ? kasan_save_stack (mm/kasan/common.c:49)
[ 1284.448485][ T4335] ? kasan_save_stack (mm/kasan/common.c:48)
[ 1284.448634][ T4335] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 1284.448782][ T4335] ? __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)
[ 1284.448978][ T4335] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 1284.449137][ T4335] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 1284.449285][ T4335] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 1284.449483][ T4335] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 1284.449640][ T4335] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 1284.449789][ T4335] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 1284.449936][ T4335] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 1284.450084][ T4335] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 1284.450238][ T4335] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 1284.450386][ T4335] __sys_sendmsg (net/socket.c:2680)
[ 1284.450532][ T4335] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 1284.450677][ T4335] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 1284.450881][ T4335] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 1284.451027][ T4335] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 1284.451208][ T4335] RIP: 0033:0x7f9ee88e39a7
[ 1284.451380][ T4335] 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)
[ 1284.451911][ T4335] RSP: 002b:00007ffe1501aa48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1284.452140][ T4335] RAX: ffffffffffffffda RBX: 00007ffe1501b170 RCX: 00007f9ee88e39a7
[ 1284.452369][ T4335] RDX: 0000000000000000 RSI: 00007ffe1501aab0 RDI: 0000000000000005
[ 1284.452600][ T4335] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[ 1284.452834][ T4335] R10: 00007f9ee87a1ef8 R11: 0000000000000246 R12: 0000000000000002


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