======================================
| [ 20.315816][ T404] #0: ffffffffae207e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [ 20.316080][ T404] #1: ffffffffae1f6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   20.316368][  T404]
| [   20.316368][  T404] stack backtrace:
[   20.316758][  T404] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   20.316938][  T404] Call Trace:
[   20.317047][  T404]  <TASK>
[ 20.317133][ T404] dump_stack_lvl (lib/dump_stack.c:123)
[ 20.317277][ T404] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 20.317419][ T404] validate_chain (kernel/locking/lockdep.c:3894)
[ 20.317559][ T404] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 20.317702][ T404] ? 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)
[ 20.317841][ T404] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 20.317966][ T404] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 20.318115][ T404] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 20.318258][ T404] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 20.318435][ T404] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 20.318578][ T404] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 20.318721][ T404] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 20.318865][ T404] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 20.319008][ T404] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 20.319201][ T404] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 20.319307][ T404] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 20.319482][ T404] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 20.319622][ T404] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 20.319761][ T404] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 20.319901][ T404] __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))
[ 20.320061][ T404] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 20.320208][ T404] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 20.320385][ T404] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 20.320564][ T404] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 20.320706][ T404] ? __pfx___try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 20.320883][ T404] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 20.321029][ T404] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 20.321174][ T404] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 20.321356][ T404] ? 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)
[ 20.321500][ T404] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 20.321645][ T404] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 20.321821][ T404] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804)
[ 20.321972][ T404] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 20.322115][ T404] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 20.322258][ T404] unregister_netdevice_many_notify (net/core/dev.c:11571)
[ 20.322438][ T404] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[ 20.322614][ T404] ? rtnl_dellink (net/core/rtnetlink.c:3512)
[ 20.322756][ T404] ? sock_def_readable (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/sock.c:3479)
[ 20.322901][ T404] ? __pfx___mutex_lock (kernel/locking/mutex.c:734)
[ 20.323049][ T404] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 20.323198][ T404] ? unregister_netdevice_queue (net/core/dev.c:11497)
[ 20.323376][ T404] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 20.323554][ T404] ? __nla_validate_parse (./include/net/netlink.h:1270 (discriminator 1) lib/nlattr.c:622 (discriminator 1))
[ 20.323699][ T404] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[ 20.323844][ T404] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 20.324005][ T404] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 20.324146][ T404] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 20.324288][ T404] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 20.324430][ T404] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 20.324587][ T404] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 20.324727][ T404] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 20.324866][ T404] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 20.325005][ T404] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 20.325147][ T404] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 20.325286][ T404] ? 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)
[ 20.325424][ T404] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 20.325534][ T404] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 20.325675][ T404] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 20.325815][ T404] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 20.325978][ T404] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 20.326127][ T404] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 20.326273][ T404] ? 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)
[ 20.326418][ T404] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 20.326565][ T404] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 20.326709][ T404] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 20.326854][ T404] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 20.326998][ T404] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 20.327154][ T404] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 20.327292][ T404] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 20.327432][ T404] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 20.327611][ T404] ___sys_sendmsg (net/socket.c:2650)
[ 20.327749][ T404] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 20.327889][ T404] ? kasan_save_stack (mm/kasan/common.c:49)
[ 20.328031][ T404] ? kasan_save_stack (mm/kasan/common.c:48)
[ 20.328171][ T404] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 20.328310][ T404] ? __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)
[ 20.328504][ T404] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 20.328652][ T404] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 20.328799][ T404] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 20.328976][ T404] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 20.329121][ T404] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 20.329263][ T404] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 20.329404][ T404] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 20.329549][ T404] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 20.329693][ T404] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 20.329842][ T404] __sys_sendmsg (net/socket.c:2680)
[ 20.329984][ T404] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 20.330127][ T404] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 20.330313][ T404] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 20.330457][ T404] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   20.330633][  T404] RIP: 0033:0x7f1b7c8b49a7
[ 20.330783][ T404] 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)
[   20.331290][  T404] RSP: 002b:00007ffeaba0f388 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   20.331505][  T404] RAX: ffffffffffffffda RBX: 00007ffeaba0fac0 RCX: 00007f1b7c8b49a7
[   20.331721][  T404] RDX: 0000000000000000 RSI: 00007ffeaba0f3f0 RDI: 0000000000000005
[   20.331939][  T404] RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000078
[   20.332153][  T404] R10: 00007f1b7c7724a8 R11: 0000000000000246 R12: 0000000000000001


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