======================================
| [765.326593][T11152] #0: ffffffffacbe7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3521)
| [765.326885][T11152] #1: ffffffffacbd6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  765.327210][T11152]
| [  765.327210][T11152] stack backtrace:
[  765.327652][T11152] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  765.327849][T11152] Call Trace:
[  765.327976][T11152]  <TASK>
[765.328062][T11152] dump_stack_lvl (lib/dump_stack.c:123)
[765.328228][T11152] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[765.328387][T11152] validate_chain (kernel/locking/lockdep.c:3894)
[765.328552][T11152] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[765.328714][T11152] ? 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)
[765.328872][T11152] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[765.328999][T11152] __lock_acquire (kernel/locking/lockdep.c:5226)
[765.329161][T11152] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[765.329320][T11152] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[765.329519][T11152] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[765.329720][T11152] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[765.329879][T11152] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[765.330042][T11152] ? lock_acquire (kernel/locking/lockdep.c:5822)
[765.330204][T11152] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[765.330412][T11152] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[765.330539][T11152] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[765.330745][T11152] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[765.330906][T11152] ? __lock_release (kernel/locking/lockdep.c:5525)
[765.331069][T11152] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[765.331233][T11152] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[765.331398][T11152] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[765.331563][T11152] __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))
[765.331727][T11152] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[765.331934][T11152] ? __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)
[765.332104][T11152] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[765.332312][T11152] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[765.332479][T11152] netdev_upper_dev_unlink (net/core/dev.c:8190)
[765.332660][T11152] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[765.332858][T11152] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[765.333021][T11152] ? 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)
[765.333181][T11152] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[765.333344][T11152] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[765.333550][T11152] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[765.333717][T11152] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[765.333878][T11152] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[765.334041][T11152] unregister_netdevice_many_notify (net/core/dev.c:11575)
[765.334237][T11152] ? 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)
[765.334396][T11152] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[765.334519][T11152] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[765.334724][T11152] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[765.334925][T11152] ? kfree (mm/slub.c:4613 mm/slub.c:4761)
[765.335047][T11152] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[765.335210][T11152] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[765.335374][T11152] rtnl_dellink (net/core/rtnetlink.c:3487 net/core/rtnetlink.c:3527)
[765.335537][T11152] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[765.335712][T11152] ? find_held_lock (kernel/locking/lockdep.c:5339)
[765.335880][T11152] ? __lock_release (kernel/locking/lockdep.c:5525)
[765.336040][T11152] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[765.336198][T11152] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[765.336357][T11152] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[765.336526][T11152] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[765.336690][T11152] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[765.336851][T11152] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[765.337015][T11152] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[765.337177][T11152] ? 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)
[765.337336][T11152] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[765.337458][T11152] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[765.337619][T11152] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[765.337777][T11152] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[765.337938][T11152] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[765.338100][T11152] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[765.338266][T11152] ? 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)
[765.338426][T11152] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[765.338589][T11152] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[765.338749][T11152] ? find_held_lock (kernel/locking/lockdep.c:5339)
[765.338911][T11152] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[765.339070][T11152] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[765.339236][T11152] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[765.339401][T11152] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[765.339563][T11152] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[765.339766][T11152] ___sys_sendmsg (net/socket.c:2650)
[765.339930][T11152] ? __pfx____sys_sendmsg (net/socket.c:2637)
[765.340089][T11152] ? kasan_save_stack (mm/kasan/common.c:49)
[765.340252][T11152] ? kasan_save_stack (mm/kasan/common.c:48)
[765.340413][T11152] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[765.340583][T11152] ? __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)
[765.340784][T11152] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[765.340945][T11152] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[765.341107][T11152] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[765.341311][T11152] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[765.341473][T11152] ? find_held_lock (kernel/locking/lockdep.c:5339)
[765.341634][T11152] ? __lock_release (kernel/locking/lockdep.c:5525)
[765.341801][T11152] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[765.341966][T11152] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[765.342127][T11152] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[765.342290][T11152] __sys_sendmsg (net/socket.c:2680)
[765.342452][T11152] ? __pfx___sys_sendmsg (net/socket.c:2665)
[765.342627][T11152] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[765.342831][T11152] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[765.342996][T11152] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  765.343193][T11152] RIP: 0033:0x7f4392ea39a7
[ 765.343366][T11152] 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)
[  765.343929][T11152] RSP: 002b:00007fff2bf5d6d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  765.344176][T11152] RAX: ffffffffffffffda RBX: 00007fff2bf5de00 RCX: 00007f4392ea39a7
[  765.344419][T11152] RDX: 0000000000000000 RSI: 00007fff2bf5d740 RDI: 0000000000000005
[  765.344664][T11152] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[  765.344906][T11152] R10: 00007f4392d61ef8 R11: 0000000000000246 R12: 0000000000000002


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