======================================
| [    5.228223] #PF: supervisor write access in kernel mode
| [    5.228285] #PF: error_code(0x0002) - not-present page
| [    5.228343] PGD 201f067 P4D 201f067 PUD 2018067 PMD 0
| [    5.228406] Oops: Oops: 0002 [#1] SMP
[    5.228558] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    5.228627] RIP: 0010:work_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072 kernel/workqueue.c:2160)
[    5.228698] Code: 83 e6 01 41 57 41 56 4c 8d 77 20 41 55 41 54 41 89 f4 55 48 89 d5 53 48 89 fb 9c 58 fa 48 89 45 00 45 85 e4 0f 85 8a 00 00 00 <f0> 48 0f ba 2b 00 41 0f 92 c5 72 0e 5b 44 89 e8 5d 41 5c 41 5d 41
All code
========
   0:	83 e6 01             	and    $0x1,%esi
   3:	41 57                	push   %r15
   5:	41 56                	push   %r14
   7:	4c 8d 77 20          	lea    0x20(%rdi),%r14
   b:	41 55                	push   %r13
   d:	41 54                	push   %r12
   f:	41 89 f4             	mov    %esi,%r12d
  12:	55                   	push   %rbp
  13:	48 89 d5             	mov    %rdx,%rbp
  16:	53                   	push   %rbx
  17:	48 89 fb             	mov    %rdi,%rbx
  1a:	9c                   	pushf
  1b:	58                   	pop    %rax
  1c:	fa                   	cli
  1d:	48 89 45 00          	mov    %rax,0x0(%rbp)
  21:	45 85 e4             	test   %r12d,%r12d
  24:	0f 85 8a 00 00 00    	jne    0xb4
  2a:*	f0 48 0f ba 2b 00    	lock btsq $0x0,(%rbx)		<-- trapping instruction
  30:	41 0f 92 c5          	setb   %r13b
  34:	72 0e                	jb     0x44
  36:	5b                   	pop    %rbx
  37:	44 89 e8             	mov    %r13d,%eax
  3a:	5d                   	pop    %rbp
  3b:	41 5c                	pop    %r12
  3d:	41 5d                	pop    %r13
  3f:	41                   	rex.B

Code starting with the faulting instruction
===========================================
   0:	f0 48 0f ba 2b 00    	lock btsq $0x0,(%rbx)
   6:	41 0f 92 c5          	setb   %r13b
   a:	72 0e                	jb     0x1a
   c:	5b                   	pop    %rbx
   d:	44 89 e8             	mov    %r13d,%eax
  10:	5d                   	pop    %rbp
  11:	41 5c                	pop    %r12
  13:	41 5d                	pop    %r13
  15:	41                   	rex.B
[    5.228895] RSP: 0018:ffffa1424059fcb8 EFLAGS: 00010046
[    5.228941] RAX: 0000000000000246 RBX: 0000000000000000 RCX: 00000000fffb800c
[    5.229007] RDX: ffffa1424059fcf0 RSI: 0000000000000000 RDI: 0000000000000000
[    5.229060] RBP: ffffa1424059fcf0 R08: 0000000000000000 R09: 000000000000038e
[    5.229118] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[    5.229174] R13: ffffa1424059fde8 R14: 0000000000000020 R15: 0000000000000000
[    5.229233] FS:  0000000038ef53c0(0000) GS:ffff8f8d79966000(0000) knlGS:0000000000000000
[    5.229298] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    5.229343] CR2: 0000000000000000 CR3: 0000000002f1c003 CR4: 0000000000772ef0
[    5.229398] PKRU: 55555554
[    5.229414] Call Trace:
[    5.229433]  <TASK>
[    5.229455]  __cancel_work (kernel/workqueue.c:4366)
[    5.229488]  ? dev_deactivate_many (net/sched/sch_generic.c:1324 net/sched/sch_generic.c:1382)
[    5.229545]  __cancel_work_sync (kernel/workqueue.c:4381)
[    5.229576]  __dev_close_many (net/core/dev.c:1879 (discriminator 2) net/core/dev.c:1932 (discriminator 2))
[    5.229613]  netif_close_many (net/core/dev.c:1959)
[    5.229643]  unregister_netdevice_many_notify (net/core/dev.c:12545)
[    5.229681]  ? __queue_work (kernel/workqueue.c:2351)
[    5.229713]  unregister_netdevice_queue (net/core/dev.c:12452)
[    5.229752]  __tun_detach (./include/linux/netdevice.h:3491 drivers/net/tun.c:621)
[    5.229787]  tun_chr_close (drivers/net/tun.c:638 drivers/net/tun.c:3436)
[    5.229818]  __fput (fs/file_table.c:469)
[    5.229861]  __x64_sys_close (fs/open.c:1592 fs/open.c:1574 fs/open.c:1574)
[    5.229893]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    5.229929]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    5.229969] RIP: 0033:0x4901eb
[    5.229999] Code: 03 00 00 00 0f 05 48 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 c3 78 04 00 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 21 79 04 00 8b 44
All code
========
   0:	03 00                	add    (%rax),%eax
   2:	00 00                	add    %al,(%rax)
   4:	0f 05                	syscall
   6:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   c:	77 41                	ja     0x4f
   e:	c3                   	ret
   f:	48 83 ec 18          	sub    $0x18,%rsp
  13:	89 7c 24 0c          	mov    %edi,0xc(%rsp)
  17:	e8 c3 78 04 00       	call   0x478df
  1c:	8b 7c 24 0c          	mov    0xc(%rsp),%edi
  20:	41 89 c0             	mov    %eax,%r8d
  23:	b8 03 00 00 00       	mov    $0x3,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 35                	ja     0x67
  32:	44 89 c7             	mov    %r8d,%edi
  35:	89 44 24 0c          	mov    %eax,0xc(%rsp)
  39:	e8 21 79 04 00       	call   0x4795f
  3e:	8b                   	.byte 0x8b
  3f:	44                   	rex.R

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 35                	ja     0x3d
   8:	44 89 c7             	mov    %r8d,%edi
   b:	89 44 24 0c          	mov    %eax,0xc(%rsp)
   f:	e8 21 79 04 00       	call   0x47935
  14:	8b                   	.byte 0x8b
  15:	44                   	rex.R
[    5.230120] RSP: 002b:00007ffc6aafb5f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
[    5.230176] RAX: ffffffffffffffda RBX: 00007ffc6aafbb48 RCX: 00000000004901eb
[    5.230231] RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000005
[    5.230286] RBP: 00007ffc6aafb630 R08: 0000000000000000 R09: 0000000000000000
[    5.230341] R10: 0000000001000000 R11: 0000000000000293 R12: 00007ffc6aafbac8


Finger prints:
work_grab_pending:__cancel_work:__cancel_work_sync:__dev_close_many:netif_close_many