======================================
| [   92.296066][   T72] ==================================================================
| [ 92.296739][ T72] 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
| [   92.297471][   T72] Read of size 8 at addr ffff888008118bd0 by task kworker/u8:1/72
| [   92.298046][   T72]
[   92.298854][   T72] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   92.299743][   T72] Workqueue: netns cleanup_net
[   92.300140][   T72] Call Trace:
[   92.300389][   T72]  <TASK>
[ 92.300628][ T72] dump_stack_lvl (lib/dump_stack.c:107) 
[ 92.300970][ T72] print_address_description.constprop.0 (mm/kasan/report.c:378) 
[ 92.301459][ T72] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 92.301964][ T72] print_report (mm/kasan/report.c:489) 
[ 92.302318][ T72] ? 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) 
[ 92.302712][ T72] kasan_report (mm/kasan/report.c:603) 
[ 92.303052][ T72] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 92.303527][ T72] vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 92.303970][ T72] ? __pfx_vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4631) vxlan
[ 92.304473][ T72] ? netconsole_netdev_event (drivers/net/netconsole.c:991) 
[ 92.304772][ T72] notifier_call_chain (kernel/notifier.c:93) 
[ 92.305034][ T72] unregister_netdevice_many_notify (net/core/dev.c:11095) 
[ 92.305374][ T72] ? 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) 
[ 92.305668][ T72] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11035) 
[ 92.306104][ T72] ? vrf_dellink (drivers/net/vrf.c:1708) vrf
[ 92.306397][ T72] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11019) 
[ 92.306719][ T72] default_device_exit_batch (net/core/dev.c:11629) 
[ 92.307040][ T72] ? __pfx_default_device_exit_batch (net/core/dev.c:11604) 
[ 92.307471][ T72] ? 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) 
[ 92.307718][ T72] ? 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) 
[ 92.308024][ T72] cleanup_net (net/core/net_namespace.c:636 (discriminator 3)) 
[ 92.308255][ T72] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 92.308641][ T72] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 92.308941][ T72] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 92.309184][ T72] ? process_one_work (kernel/workqueue.c:2609) 
[ 92.309458][ T72] process_one_work (kernel/workqueue.c:2633) 
[ 92.309713][ T72] ? 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) 
[ 92.310023][ T72] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 92.310374][ T72] ? assign_work (kernel/workqueue.c:1101) 
[ 92.310612][ T72] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 92.310854][ T72] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 92.311191][ T72] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 92.311569][ T72] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 92.311870][ T72] kthread (kernel/kthread.c:388) 
[ 92.312080][ T72] ? __pfx_kthread (kernel/kthread.c:341) 
[ 92.312327][ T72] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 92.312560][ T72] ? __pfx_kthread (kernel/kthread.c:341) 
[ 92.312838][ T72] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   92.334066][   T72] ==================================================================
| [   92.334795][   T72] Disabling lock debugging due to kernel taint
| [   92.335132][   T72] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [   92.335917][   T72] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[   92.336824][   T72] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   92.337601][   T72] Workqueue: netns cleanup_net
[ 92.337850][ T72] RIP: 0010:vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 92.338210][ T72] 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
[   92.339371][   T72] RSP: 0018:ffffc9000051f980 EFLAGS: 00010246
[   92.339681][   T72] RAX: 0000000000000000 RBX: ffffffffffffffd0 RCX: dffffc0000000000
[   92.340212][   T72] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888008118c24
[   92.340624][   T72] RBP: 1ffff920000a3f33 R08: 1ffff11000e1021a R09: ffffc9000051f9b8
[   92.341024][   T72] R10: ffffffff9313ca07 R11: 205d323754202020 R12: ffffed1000e1021a
[   92.341559][   T72] R13: ffff888008118ba0 R14: ffff888009e14000 R15: ffff888007081000
[   92.341963][   T72] FS:  0000000000000000(0000) GS:ffff888035600000(0000) knlGS:0000000000000000
[   92.342420][   T72] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   92.342868][   T72] CR2: 00007f927e9f5000 CR3: 000000002951e002 CR4: 0000000000770ef0
[   92.343282][   T72] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   92.343756][   T72] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   92.344348][   T72] PKRU: 55555554
[   92.344547][   T72] Call Trace:
[   92.344718][   T72]  <TASK>
[ 92.344892][ T72] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 92.345123][ T72] ? exc_general_protection (arch/x86/kernel/traps.c:701 arch/x86/kernel/traps.c:643) 
[ 92.345476][ T72] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:564) 
[ 92.345900][ T72] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 92.346261][ T72] ? __pfx_vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4631) vxlan
[ 92.346627][ T72] ? netconsole_netdev_event (drivers/net/netconsole.c:991) 
[ 92.347033][ T72] notifier_call_chain (kernel/notifier.c:93) 
[ 92.347418][ T72] unregister_netdevice_many_notify (net/core/dev.c:11095) 
[ 92.347780][ T72] ? 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) 
[ 92.348043][ T72] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11035) 
[ 92.348523][ T72] ? vrf_dellink (drivers/net/vrf.c:1708) vrf
[ 92.348833][ T72] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11019) 
[ 92.349187][ T72] default_device_exit_batch (net/core/dev.c:11629) 
[ 92.349486][ T72] ? __pfx_default_device_exit_batch (net/core/dev.c:11604) 
[ 92.349885][ T72] ? 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) 
[ 92.350183][ T72] ? 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) 
[ 92.350493][ T72] cleanup_net (net/core/net_namespace.c:636 (discriminator 3)) 
[ 92.350723][ T72] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 92.351009][ T72] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 92.351363][ T72] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 92.351646][ T72] ? process_one_work (kernel/workqueue.c:2609) 
[ 92.351911][ T72] process_one_work (kernel/workqueue.c:2633) 
[ 92.352166][ T72] ? 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) 
[ 92.352411][ T72] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 92.352775][ T72] ? assign_work (kernel/workqueue.c:1101) 
[ 92.353059][ T72] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 92.353302][ T72] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 92.353647][ T72] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 92.353909][ T72] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 92.354296][ T72] kthread (kernel/kthread.c:388) 
[ 92.354546][ T72] ? __pfx_kthread (kernel/kthread.c:341) 
[ 92.354781][ T72] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 92.355009][ T72] ? __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