======================================
| [853.962352][T10727] #0: ffffffff9e7e7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3521)
| [853.962673][T10727] #1: ffffffff9e7d6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  853.962984][T10727]
| [  853.962984][T10727] stack backtrace:
[  853.963394][T10727] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  853.963581][T10727] Call Trace:
[  853.963697][T10727]  <TASK>
[853.963776][T10727] dump_stack_lvl (lib/dump_stack.c:123)
[853.963930][T10727] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[853.964079][T10727] validate_chain (kernel/locking/lockdep.c:3894)
[853.964238][T10727] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[853.964391][T10727] ? 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)
[853.964542][T10727] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[853.964657][T10727] __lock_acquire (kernel/locking/lockdep.c:5226)
[853.964822][T10727] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[853.964976][T10727] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[853.965165][T10727] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[853.965357][T10727] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[853.965511][T10727] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[853.965659][T10727] ? lock_acquire (kernel/locking/lockdep.c:5822)
[853.965810][T10727] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[853.965996][T10727] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[853.966112][T10727] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[853.966297][T10727] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[853.966444][T10727] ? __lock_release (kernel/locking/lockdep.c:5525)
[853.966592][T10727] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[853.966749][T10727] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[853.966913][T10727] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[853.967065][T10727] __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))
[853.967215][T10727] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[853.967405][T10727] ? __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)
[853.967555][T10727] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[853.967744][T10727] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[853.967901][T10727] netdev_upper_dev_unlink (net/core/dev.c:8190)
[853.968053][T10727] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[853.968235][T10727] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[853.968383][T10727] ? 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)
[853.968535][T10727] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[853.968683][T10727] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[853.968894][T10727] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[853.969052][T10727] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[853.969202][T10727] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[853.969355][T10727] unregister_netdevice_many_notify (net/core/dev.c:11575)
[853.969538][T10727] ? 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)
[853.969690][T10727] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[853.969811][T10727] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[853.969999][T10727] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[853.970188][T10727] ? kfree (mm/slub.c:4613 mm/slub.c:4761)
[853.970301][T10727] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[853.970459][T10727] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[853.970609][T10727] rtnl_dellink (net/core/rtnetlink.c:3487 net/core/rtnetlink.c:3527)
[853.970765][T10727] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[853.970934][T10727] ? find_held_lock (kernel/locking/lockdep.c:5339)
[853.971085][T10727] ? __lock_release (kernel/locking/lockdep.c:5525)
[853.971246][T10727] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[853.971402][T10727] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[853.971552][T10727] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[853.971708][T10727] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[853.971857][T10727] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[853.972010][T10727] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[853.972159][T10727] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[853.972310][T10727] ? 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)
[853.972459][T10727] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[853.972573][T10727] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[853.972722][T10727] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[853.972871][T10727] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[853.973026][T10727] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[853.973178][T10727] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[853.973329][T10727] ? 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)
[853.973480][T10727] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[853.973630][T10727] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[853.973775][T10727] ? find_held_lock (kernel/locking/lockdep.c:5339)
[853.973953][T10727] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[853.974110][T10727] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[853.974263][T10727] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[853.974412][T10727] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[853.974560][T10727] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[853.974748][T10727] ___sys_sendmsg (net/socket.c:2650)
[853.974896][T10727] ? __pfx____sys_sendmsg (net/socket.c:2637)
[853.975044][T10727] ? kasan_save_stack (mm/kasan/common.c:49)
[853.975197][T10727] ? kasan_save_stack (mm/kasan/common.c:48)
[853.975343][T10727] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[853.975496][T10727] ? __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)
[853.975683][T10727] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[853.975830][T10727] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[853.975979][T10727] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[853.976163][T10727] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[853.976317][T10727] ? find_held_lock (kernel/locking/lockdep.c:5339)
[853.976471][T10727] ? __lock_release (kernel/locking/lockdep.c:5525)
[853.976621][T10727] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[853.976771][T10727] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[853.976919][T10727] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[853.977073][T10727] __sys_sendmsg (net/socket.c:2680)
[853.977224][T10727] ? __pfx___sys_sendmsg (net/socket.c:2665)
[853.977372][T10727] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[853.977566][T10727] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[853.977717][T10727] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  853.977898][T10727] RIP: 0033:0x7f901e4929a7
[ 853.978059][T10727] 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)
[  853.978581][T10727] RSP: 002b:00007ffdf1b075c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  853.978805][T10727] RAX: ffffffffffffffda RBX: 00007ffdf1b07cf0 RCX: 00007f901e4929a7
[  853.979036][T10727] RDX: 0000000000000000 RSI: 00007ffdf1b07630 RDI: 0000000000000005
[  853.979257][T10727] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[  853.979494][T10727] R10: 00007f901e350ef8 R11: 0000000000000246 R12: 0000000000000002


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