======================================
| [  400.075988][   T67] ==================================================================
| [ 400.076508][ T67] BUG: KASAN: slab-use-after-free in vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
| [  400.077109][   T67] Read of size 8 at addr ffff8880080e8bd0 by task kworker/u8:1/67
| [  400.077557][   T67]
[  400.078192][   T67] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  400.078985][   T67] Workqueue: netns cleanup_net
[  400.079284][   T67] Call Trace:
[  400.079470][   T67]  <TASK>
[ 400.079662][ T67] dump_stack_lvl (lib/dump_stack.c:107) 
[ 400.079978][ T67] print_address_description.constprop.0 (mm/kasan/report.c:378) 
[ 400.080377][ T67] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 400.080760][ T67] print_report (mm/kasan/report.c:489) 
[ 400.081023][ T67] ? kasan_addr_to_slab (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 ./include/linux/page-flags.h:481 mm/kasan/../slab.h:206 mm/kasan/common.c:38) 
[ 400.081343][ T67] kasan_report (mm/kasan/report.c:603) 
[ 400.081580][ T67] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 400.081944][ T67] vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 400.082325][ T67] ? __pfx_vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4631) vxlan
[ 400.082709][ T67] ? netconsole_netdev_event (drivers/net/netconsole.c:991) 
[ 400.083075][ T67] notifier_call_chain (kernel/notifier.c:93) 
[ 400.083395][ T67] unregister_netdevice_many_notify (net/core/dev.c:11095) 
[ 400.083762][ T67] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2569 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3161 kernel/locking/mutex.c:81 kernel/locking/mutex.c:91) 
[ 400.084055][ T67] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11035) 
[ 400.084464][ T67] ? vrf_dellink (drivers/net/vrf.c:1708) vrf
[ 400.084784][ T67] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11019) 
[ 400.085141][ T67] default_device_exit_batch (net/core/dev.c:11629) 
[ 400.085450][ T67] ? __pfx_default_device_exit_batch (net/core/dev.c:11604) 
[ 400.085845][ T67] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2569 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3161 kernel/locking/mutex.c:81 kernel/locking/mutex.c:91) 
[ 400.086089][ T67] ? nexthop_net_exit_batch_rtnl (net/ipv4/nexthop.c:569 net/ipv4/nexthop.c:1918 net/ipv4/nexthop.c:2426 net/ipv4/nexthop.c:3754) 
[ 400.086391][ T67] cleanup_net (net/core/net_namespace.c:636 (discriminator 3)) 
[ 400.086659][ T67] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 400.086979][ T67] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 400.087230][ T67] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 400.087487][ T67] ? process_one_work (kernel/workqueue.c:2609) 
[ 400.087761][ T67] process_one_work (kernel/workqueue.c:2633) 
[ 400.088048][ T67] ? 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) 
[ 400.088300][ T67] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 400.088628][ T67] ? assign_work (kernel/workqueue.c:1101) 
[ 400.088863][ T67] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 400.089111][ T67] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 400.089458][ T67] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 400.089771][ T67] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 400.090032][ T67] kthread (kernel/kthread.c:388) 
[ 400.090242][ T67] ? __pfx_kthread (kernel/kthread.c:341) 
[ 400.090476][ T67] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 400.090735][ T67] ? __pfx_kthread (kernel/kthread.c:341) 
[ 400.091000][ T67] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [  400.111434][   T67] ==================================================================
| [  400.112620][   T67] Disabling lock debugging due to kernel taint
| [  400.113025][   T67] general protection fault, probably for non-canonical address 0xed6d696d6d6d6d6d: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [  400.113745][   T67] KASAN: maybe wild-memory-access in range [0x6b6b6b6b6b6b6b68-0x6b6b6b6b6b6b6b6f]
[  400.114896][   T67] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  400.115685][   T67] Workqueue: netns cleanup_net
[ 400.115970][ T67] RIP: 0010:vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 400.116433][ T67] Code: 00 00 00 48 b9 00 00 00 00 00 fc ff df 49 89 c0 48 89 44 24 08 49 c1 e8 03 4d 8d 24 08 eb 2c 48 8d 53 30 48 89 d0 48 c1 e8 03 <80> 3c 08 00 0f 85 e0 00 00 00 48 8b 43 30 49 89 dd 48 83 e8 30 49
All code
========
   0:	00 00                	add    %al,(%rax)
   2:	00 48 b9             	add    %cl,-0x47(%rax)
   5:	00 00                	add    %al,(%rax)
   7:	00 00                	add    %al,(%rax)
   9:	00 fc                	add    %bh,%ah
   b:	ff                   	(bad)
   c:	df 49 89             	fisttps -0x77(%rcx)
   f:	c0 48 89 44          	rorb   $0x44,-0x77(%rax)
  13:	24 08                	and    $0x8,%al
  15:	49 c1 e8 03          	shr    $0x3,%r8
  19:	4d 8d 24 08          	lea    (%r8,%rcx,1),%r12
  1d:	eb 2c                	jmp    0x4b
  1f:	48 8d 53 30          	lea    0x30(%rbx),%rdx
  23:	48 89 d0             	mov    %rdx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
  2a:*	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1)		<-- trapping instruction
  2e:	0f 85 e0 00 00 00    	jne    0x114
  34:	48 8b 43 30          	mov    0x30(%rbx),%rax
  38:	49 89 dd             	mov    %rbx,%r13
  3b:	48 83 e8 30          	sub    $0x30,%rax
  3f:	49                   	rex.WB

Code starting with the faulting instruction
===========================================
   0:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1)
   4:	0f 85 e0 00 00 00    	jne    0xea
   a:	48 8b 43 30          	mov    0x30(%rbx),%rax
   e:	49 89 dd             	mov    %rbx,%r13
  11:	48 83 e8 30          	sub    $0x30,%rax
  15:	49                   	rex.WB
[  400.117608][   T67] RSP: 0018:ffffc900004df980 EFLAGS: 00010202
[  400.117957][   T67] RAX: 0d6d6d6d6d6d6d6d RBX: 6b6b6b6b6b6b6b3b RCX: dffffc0000000000
[  400.118422][   T67] RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000004 RDI: ffff8880080e8c24
[  400.118892][   T67] RBP: 1ffff9200009bf33 R08: 1ffff1100144b81a R09: ffffc900004df9b8
[  400.119366][   T67] R10: ffffffff89f3ca07 R11: 205d373654202020 R12: ffffed100144b81a
[  400.119877][   T67] R13: ffff8880080e8ba0 R14: ffff8880060f4000 R15: ffff88800a25c000
[  400.120385][   T67] FS:  0000000000000000(0000) GS:ffff888035600000(0000) knlGS:0000000000000000
[  400.120917][   T67] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  400.121299][   T67] CR2: 00005572b6055368 CR3: 0000000008fb2003 CR4: 0000000000770ef0
[  400.121781][   T67] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  400.122247][   T67] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  400.122706][   T67] PKRU: 55555554
[  400.122927][   T67] Call Trace:
[  400.123136][   T67]  <TASK>
[ 400.123287][ T67] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 400.123524][ T67] ? exc_general_protection (arch/x86/kernel/traps.c:701 arch/x86/kernel/traps.c:643) 
[ 400.123867][ T67] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:564) 
[ 400.124216][ T67] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 400.124562][ T67] ? __pfx_vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4631) vxlan
[ 400.124958][ T67] ? netconsole_netdev_event (drivers/net/netconsole.c:991) 
[ 400.125246][ T67] notifier_call_chain (kernel/notifier.c:93) 
[ 400.125507][ T67] unregister_netdevice_many_notify (net/core/dev.c:11095) 
[ 400.125880][ T67] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2569 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3161 kernel/locking/mutex.c:81 kernel/locking/mutex.c:91) 
[ 400.126155][ T67] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11035) 
[ 400.126535][ T67] ? vrf_dellink (drivers/net/vrf.c:1708) vrf
[ 400.126824][ T67] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11019) 
[ 400.127212][ T67] default_device_exit_batch (net/core/dev.c:11629) 
[ 400.127542][ T67] ? __pfx_default_device_exit_batch (net/core/dev.c:11604) 
[ 400.127912][ T67] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2569 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3161 kernel/locking/mutex.c:81 kernel/locking/mutex.c:91) 
[ 400.128201][ T67] ? nexthop_net_exit_batch_rtnl (net/ipv4/nexthop.c:569 net/ipv4/nexthop.c:1918 net/ipv4/nexthop.c:2426 net/ipv4/nexthop.c:3754) 
[ 400.128504][ T67] cleanup_net (net/core/net_namespace.c:636 (discriminator 3)) 
[ 400.128785][ T67] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 400.129107][ T67] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 400.129385][ T67] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 400.129660][ T67] ? process_one_work (kernel/workqueue.c:2609) 
[ 400.130012][ T67] process_one_work (kernel/workqueue.c:2633) 
[ 400.130312][ T67] ? 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) 
[ 400.130550][ T67] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 400.130876][ T67] ? assign_work (kernel/workqueue.c:1101) 
[ 400.131114][ T67] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 400.131398][ T67] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 400.131770][ T67] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 400.132082][ T67] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 400.132412][ T67] kthread (kernel/kthread.c:388) 
[ 400.132653][ T67] ? __pfx_kthread (kernel/kthread.c:341) 
[ 400.132901][ T67] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 400.133161][ T67] ? __pfx_kthread (kernel/kthread.c:341) 


Finger prints:
dump_stack_lvl:print_report:kasan_report:vxlan_netdevice_event
vxlan_netdevice_event:notifier_call_chain:unregister_netdevice_many_notify:default_device_exit_batch