======================================
| [844.227316][T17591] #0: ffffffffa5fe7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [844.227584][T17591] #1: ffffffffa5fd6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  844.227879][T17591]
| [  844.227879][T17591] stack backtrace:
[  844.228286][T17591] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  844.228469][T17591] Call Trace:
[  844.228583][T17591]  <TASK>
[844.228660][T17591] dump_stack_lvl (lib/dump_stack.c:123)
[844.228813][T17591] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[844.228960][T17591] validate_chain (kernel/locking/lockdep.c:3894)
[844.229113][T17591] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[844.229259][T17591] ? 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)
[844.229403][T17591] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[844.229514][T17591] __lock_acquire (kernel/locking/lockdep.c:5226)
[844.229665][T17591] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[844.229813][T17591] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[844.229993][T17591] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[844.230198][T17591] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[844.230344][T17591] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[844.230490][T17591] ? lock_acquire (kernel/locking/lockdep.c:5822)
[844.230634][T17591] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[844.230817][T17591] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[844.230928][T17591] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[844.231114][T17591] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[844.231266][T17591] ? __lock_release (kernel/locking/lockdep.c:5525)
[844.231414][T17591] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[844.231560][T17591] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[844.231706][T17591] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[844.231852][T17591] __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))
[844.231999][T17591] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[844.232179][T17591] ? __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)
[844.232330][T17591] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[844.232515][T17591] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[844.232664][T17591] netdev_upper_dev_unlink (net/core/dev.c:8190)
[844.232809][T17591] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[844.232993][T17591] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[844.233138][T17591] ? 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)
[844.233284][T17591] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[844.233436][T17591] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[844.233619][T17591] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[844.233771][T17591] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[844.233920][T17591] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[844.234090][T17591] unregister_netdevice_many_notify (net/core/dev.c:11571)
[844.234301][T17591] ? 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)
[844.234448][T17591] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[844.234563][T17591] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[844.234744][T17591] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[844.234928][T17591] ? kfree (mm/slub.c:4613 mm/slub.c:4761)
[844.235042][T17591] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[844.235192][T17591] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[844.235337][T17591] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[844.235487][T17591] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[844.235653][T17591] ? find_held_lock (kernel/locking/lockdep.c:5339)
[844.235801][T17591] ? __lock_release (kernel/locking/lockdep.c:5525)
[844.235967][T17591] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[844.236111][T17591] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[844.236256][T17591] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[844.236404][T17591] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[844.236550][T17591] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[844.236704][T17591] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[844.236855][T17591] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[844.237000][T17591] ? 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)
[844.237145][T17591] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[844.237260][T17591] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[844.237407][T17591] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[844.237555][T17591] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[844.237701][T17591] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[844.237857][T17591] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[844.238005][T17591] ? 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)
[844.238152][T17591] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[844.238298][T17591] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[844.238445][T17591] ? find_held_lock (kernel/locking/lockdep.c:5339)
[844.238594][T17591] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[844.238742][T17591] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[844.238901][T17591] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[844.239049][T17591] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[844.239193][T17591] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[844.239381][T17591] ___sys_sendmsg (net/socket.c:2650)
[844.239529][T17591] ? __pfx____sys_sendmsg (net/socket.c:2637)
[844.239682][T17591] ? kasan_save_stack (mm/kasan/common.c:49)
[844.239831][T17591] ? kasan_save_stack (mm/kasan/common.c:48)
[844.239982][T17591] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[844.240137][T17591] ? __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)
[844.240319][T17591] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[844.240468][T17591] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[844.240612][T17591] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[844.240795][T17591] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[844.240946][T17591] ? find_held_lock (kernel/locking/lockdep.c:5339)
[844.241097][T17591] ? __lock_release (kernel/locking/lockdep.c:5525)
[844.241242][T17591] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[844.241388][T17591] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[844.241534][T17591] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[844.241683][T17591] __sys_sendmsg (net/socket.c:2680)
[844.241830][T17591] ? __pfx___sys_sendmsg (net/socket.c:2665)
[844.241976][T17591] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[844.242169][T17591] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[844.242314][T17591] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  844.242495][T17591] RIP: 0033:0x7f56ac37e9a7
[ 844.242654][T17591] 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)
[  844.243174][T17591] RSP: 002b:00007fff57f73bf8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  844.243398][T17591] RAX: ffffffffffffffda RBX: 00007fff57f74320 RCX: 00007f56ac37e9a7
[  844.243706][T17591] RDX: 0000000000000000 RSI: 00007fff57f73c60 RDI: 0000000000000005
[  844.243928][T17591] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[  844.244155][T17591] R10: 00007f56ac23cef8 R11: 0000000000000246 R12: 0000000000000002


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