======================================
| [  222.836065][   T11] ==================================================================
| [ 222.836553][ T11] BUG: KASAN: use-after-free in vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
| [  222.837028][   T11] Read of size 8 at addr ffff88800a818bf0 by task kworker/u8:0/11
| [  222.837458][   T11]
[  222.838021][   T11] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  222.838691][   T11] Workqueue: netns cleanup_net
[  222.838978][   T11] Call Trace:
[  222.839165][   T11]  <TASK>
[ 222.839319][ T11] dump_stack_lvl (lib/dump_stack.c:107) 
[ 222.839585][ T11] print_address_description.constprop.0 (mm/kasan/report.c:378) 
[ 222.839957][ T11] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 222.840305][ T11] print_report (mm/kasan/report.c:489) 
[ 222.840547][ T11] ? 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) 
[ 222.840830][ T11] kasan_report (mm/kasan/report.c:603) 
[ 222.841084][ T11] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 222.841417][ T11] vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 222.841740][ T11] ? __pfx_vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4631) vxlan
[ 222.842088][ T11] ? nft_offload_netdev_event (net/netfilter/nf_tables_offload.c:677) nf_tables
[ 222.842512][ T11] notifier_call_chain (kernel/notifier.c:93) 
[ 222.842777][ T11] unregister_netdevice_many_notify (net/core/dev.c:11095) 
[ 222.843104][ T11] ? 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) 
[ 222.843353][ T11] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11035) 
[ 222.843699][ T11] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11019) 
[ 222.844022][ T11] default_device_exit_batch (net/core/dev.c:11629) 
[ 222.844311][ T11] ? __pfx_default_device_exit_batch (net/core/dev.c:11604) 
[ 222.844626][ T11] ? 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) 
[ 222.844874][ T11] ? 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) 
[ 222.845181][ T11] cleanup_net (net/core/net_namespace.c:636 (discriminator 3)) 
[ 222.845410][ T11] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 222.845704][ T11] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 222.845962][ T11] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 222.846204][ T11] ? process_one_work (kernel/workqueue.c:2609) 
[ 222.846472][ T11] process_one_work (kernel/workqueue.c:2633) 
[ 222.846730][ T11] ? 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) 
[ 222.846965][ T11] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 222.847253][ T11] ? assign_work (kernel/workqueue.c:1101) 
[ 222.847497][ T11] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 222.847765][ T11] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 222.848065][ T11] kthread (kernel/kthread.c:388) 
[ 222.848303][ T11] ? __pfx_kthread (kernel/kthread.c:341) 
[ 222.848546][ T11] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 222.848784][ T11] ? __pfx_kthread (kernel/kthread.c:341) 
[ 222.849054][ T11] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| # udp tx:     11 MB/s      199 calls/s    199 msg/s
| # udp rx:     11 MB/s     9696 calls/s
| [  245.219681][   T11] general protection fault, probably for non-canonical address 0xf999959999999999: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [  245.220402][   T11] KASAN: maybe wild-memory-access in range [0xccccccccccccccc8-0xcccccccccccccccf]
[  245.221443][   T11] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  245.222114][   T11] Workqueue: netns cleanup_net
[ 245.222398][ T11] RIP: 0010:vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 245.222778][ T11] 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
[  245.223889][   T11] RSP: 0018:ffffc900000bf980 EFLAGS: 00010a07
[  245.224235][   T11] RAX: 1999999999999999 RBX: cccccccccccccc9c RCX: dffffc0000000000
[  245.224704][   T11] RDX: cccccccccccccccc RSI: 0000000000000004 RDI: ffff888006b58c44
[  245.225150][   T11] RBP: 1ffff92000017f33 R08: 1ffff1100141721a R09: ffffc900000bf9b8
[  245.225581][   T11] R10: ffffffffad750f57 R11: ffff88800a0b9000 R12: ffffed100141721a
[  245.225996][   T11] R13: ffff888006b58bc0 R14: ffff888005a14000 R15: ffff88800a0b9000
[  245.226399][   T11] FS:  0000000000000000(0000) GS:ffff888035600000(0000) knlGS:0000000000000000
[  245.226852][   T11] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  245.227190][   T11] CR2: 00007f53af858000 CR3: 0000000016134001 CR4: 0000000000770ef0
[  245.227598][   T11] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  245.228003][   T11] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  245.228409][   T11] PKRU: 55555554
[  245.228593][   T11] Call Trace:
[  245.228767][   T11]  <TASK>
[ 245.228927][ T11] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 245.229148][ T11] ? exc_general_protection (arch/x86/kernel/traps.c:701 arch/x86/kernel/traps.c:643) 
[ 245.229437][ T11] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:564) 
[ 245.229734][ T11] ? vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4613 drivers/net/vxlan/vxlan_core.c:4636) vxlan
[ 245.230068][ T11] ? __pfx_vxlan_netdevice_event (drivers/net/vxlan/vxlan_core.c:4631) vxlan
[ 245.230415][ T11] ? nft_offload_netdev_event (net/netfilter/nf_tables_offload.c:677) nf_tables
[ 245.230812][ T11] ? addrconf_notify (net/ipv6/addrconf.c:3753) 
[ 245.231109][ T11] notifier_call_chain (kernel/notifier.c:93) 
[ 245.231381][ T11] unregister_netdevice_many_notify (net/core/dev.c:11095) 
[ 245.231711][ T11] ? 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) 
[ 245.231971][ T11] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11035) 
[ 245.232329][ T11] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11019) 
[ 245.232660][ T11] ? __wake_up (kernel/sched/wait.c:110 kernel/sched/wait.c:127) 
[ 245.232885][ T11] default_device_exit_batch (net/core/dev.c:11629) 
[ 245.233208][ T11] ? __pfx_default_device_exit_batch (net/core/dev.c:11604) 
[ 245.233608][ T11] ? 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) 
[ 245.233893][ T11] ? 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) 
[ 245.234231][ T11] cleanup_net (net/core/net_namespace.c:636 (discriminator 3)) 
[ 245.234486][ T11] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 245.234736][ T11] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 245.235017][ T11] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 245.235288][ T11] ? process_one_work (kernel/workqueue.c:2609) 
[ 245.235581][ T11] process_one_work (kernel/workqueue.c:2633) 
[ 245.235864][ T11] ? 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) 
[ 245.236131][ T11] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 245.236421][ T11] ? assign_work (kernel/workqueue.c:1101) 
[ 245.236668][ T11] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 245.236933][ T11] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 245.237222][ T11] kthread (kernel/kthread.c:388) 
[ 245.237455][ T11] ? __pfx_kthread (kernel/kthread.c:341) 
[ 245.237699][ T11] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 245.237954][ T11] ? __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