======================================
| [901.329442][T10538] #0: ffffffffb3be7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3521)
| [901.329742][T10538] #1: ffffffffb3bd6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  901.330095][T10538]
| [  901.330095][T10538] stack backtrace:
[  901.330568][T10538] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  901.330761][T10538] Call Trace:
[  901.330887][T10538]  <TASK>
[901.330974][T10538] dump_stack_lvl (lib/dump_stack.c:123)
[901.331159][T10538] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[901.331322][T10538] validate_chain (kernel/locking/lockdep.c:3894)
[901.331487][T10538] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[901.331645][T10538] ? 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)
[901.331800][T10538] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[901.331939][T10538] __lock_acquire (kernel/locking/lockdep.c:5226)
[901.332114][T10538] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[901.332269][T10538] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[901.332457][T10538] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[901.332645][T10538] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[901.332796][T10538] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[901.332964][T10538] ? lock_acquire (kernel/locking/lockdep.c:5822)
[901.333125][T10538] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[901.333323][T10538] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[901.333441][T10538] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[901.333629][T10538] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[901.333777][T10538] ? __lock_release (kernel/locking/lockdep.c:5525)
[901.333927][T10538] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[901.334086][T10538] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[901.334245][T10538] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[901.334407][T10538] __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))
[901.334565][T10538] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[901.334763][T10538] ? __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)
[901.334923][T10538] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[901.335128][T10538] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[901.335284][T10538] netdev_upper_dev_unlink (net/core/dev.c:8190)
[901.335438][T10538] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[901.335628][T10538] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[901.335784][T10538] ? 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)
[901.335942][T10538] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[901.336094][T10538] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[901.336296][T10538] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[901.336454][T10538] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[901.336607][T10538] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[901.336762][T10538] unregister_netdevice_many_notify (net/core/dev.c:11575)
[901.336950][T10538] ? 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)
[901.337116][T10538] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[901.337237][T10538] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[901.337419][T10538] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[901.337630][T10538] ? kfree (mm/slub.c:4613 mm/slub.c:4761)
[901.337756][T10538] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[901.337913][T10538] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[901.338105][T10538] rtnl_dellink (net/core/rtnetlink.c:3487 net/core/rtnetlink.c:3527)
[901.338266][T10538] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[901.338431][T10538] ? find_held_lock (kernel/locking/lockdep.c:5339)
[901.338590][T10538] ? __lock_release (kernel/locking/lockdep.c:5525)
[901.338736][T10538] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[901.338882][T10538] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[901.339027][T10538] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[901.339191][T10538] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[901.339340][T10538] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[901.339491][T10538] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[901.339637][T10538] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[901.339787][T10538] ? 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)
[901.339939][T10538] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[901.340061][T10538] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[901.340219][T10538] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[901.340392][T10538] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[901.340538][T10538] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[901.340686][T10538] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[901.340847][T10538] ? 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)
[901.340995][T10538] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[901.341201][T10538] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[901.341431][T10538] ? find_held_lock (kernel/locking/lockdep.c:5339)
[901.341671][T10538] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[901.341927][T10538] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[901.342103][T10538] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[901.342253][T10538] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[901.342398][T10538] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[901.342628][T10538] ___sys_sendmsg (net/socket.c:2650)
[901.342834][T10538] ? __pfx____sys_sendmsg (net/socket.c:2637)
[901.342993][T10538] ? kasan_save_stack (mm/kasan/common.c:49)
[901.343211][T10538] ? kasan_save_stack (mm/kasan/common.c:48)
[901.343364][T10538] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[901.343557][T10538] ? __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)
[901.343855][T10538] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[901.344028][T10538] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[901.344228][T10538] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[901.344435][T10538] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[901.344651][T10538] ? find_held_lock (kernel/locking/lockdep.c:5339)
[901.344803][T10538] ? __lock_release (kernel/locking/lockdep.c:5525)
[901.344948][T10538] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[901.345099][T10538] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[901.345247][T10538] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[901.345397][T10538] __sys_sendmsg (net/socket.c:2680)
[901.345557][T10538] ? __pfx___sys_sendmsg (net/socket.c:2665)
[901.345716][T10538] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[901.345907][T10538] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[901.346055][T10538] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  901.346237][T10538] RIP: 0033:0x7f59a59de9a7
[ 901.346396][T10538] 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)
[  901.346989][T10538] RSP: 002b:00007ffd9885ee08 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  901.347263][T10538] RAX: ffffffffffffffda RBX: 00007ffd9885f530 RCX: 00007f59a59de9a7
[  901.347537][T10538] RDX: 0000000000000000 RSI: 00007ffd9885ee70 RDI: 0000000000000005
[  901.347897][T10538] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[  901.348222][T10538] R10: 00007f59a589cef8 R11: 0000000000000246 R12: 0000000000000002


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