======================================
| [   18.485804][  T232] ==================================================================
| [   18.486229][  T232] BUG: KASAN: null-ptr-deref in try_to_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072)
| [   18.486564][  T232] Write of size 8 at addr 0000000000000000 by task packetdrill/232
| [   18.486861][  T232]
[   18.486990][  T232] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   18.486993][  T232] Call Trace:
[   18.486995][  T232]  <TASK>
[   18.486998][  T232]  dump_stack_lvl (lib/dump_stack.c:123)
[   18.487007][  T232]  ? try_to_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072)
[   18.487011][  T232]  kasan_report (mm/kasan/report.c:597)
[   18.487018][  T232]  ? try_to_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072)
[   18.487024][  T232]  kasan_check_range (mm/kasan/generic.c:194 mm/kasan/generic.c:200)
[   18.487028][  T232]  try_to_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072)
[   18.487034][  T232]  __cancel_work (kernel/workqueue.c:2161 kernel/workqueue.c:4364)
[   18.487037][  T232]  ? enable_delayed_work (kernel/workqueue.c:4359)
[   18.487042][  T232]  ? qdisc_destroy (net/sched/sch_generic.c:1355)
[   18.487049][  T232]  __cancel_work_sync (kernel/workqueue.c:4383)
[   18.487054][  T232]  __dev_close_many (net/core/dev.c:1879 (discriminator 2) net/core/dev.c:1932 (discriminator 2))
[   18.487059][  T232]  ? netdev_notify_peers (net/core/dev.c:1891)
[   18.487063][  T232]  ? netif_close_many (net/core/dev.c:1959)
[   18.487067][  T232]  netif_close_many (net/core/dev.c:1959)
[   18.487070][  T232]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[   18.487078][  T232]  ? __dev_close_many (net/core/dev.c:1949)
[   18.487081][  T232]  ? netif_close_many_and_unlock (net/core/dev.c:12476)
[   18.487087][  T232]  unregister_netdevice_many_notify (net/core/dev.c:12545)
[   18.487097][  T232]  ? sched_ttwu_pending (kernel/sched/core.c:4144)
[   18.487104][  T232]  ? dev_ingress_queue_create (net/core/dev.c:12499)
[   18.487110][  T232]  ? irqentry_exit (kernel/entry/common.c:215)
[   18.487115][  T232]  ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4472)
[   18.487120][  T232]  unregister_netdevice_queue (net/core/dev.c:12452)
[   18.487123][  T232]  ? unregister_netdevice_many (net/core/dev.c:12441)
[   18.487128][  T232]  ? queue_delayed_work_on (kernel/workqueue.c:2567)
[   18.487133][  T232]  __tun_detach (./include/linux/netdevice.h:3491 drivers/net/tun.c:621)
[   18.487142][  T232]  tun_chr_close (drivers/net/tun.c:638 drivers/net/tun.c:3436)
[   18.487146][  T232]  __fput (fs/file_table.c:468)
[   18.487154][  T232]  fput_close_sync (fs/file_table.c:571)
[   18.487157][  T232]  ? alloc_file_clone (fs/file_table.c:571)
[   18.487162][  T232]  __x64_sys_close (fs/open.c:1592 fs/open.c:1574 fs/open.c:1574)
[   18.487166][  T232]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[   18.487172][  T232]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   18.487176][  T232] RIP: 0033:0x4901eb
[   18.487180][  T232] 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
[   18.487183][  T232] RSP: 002b:00007fff4f496030 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
[   18.487187][  T232] RAX: ffffffffffffffda RBX: 00007fff4f496590 RCX: 00000000004901eb
[   18.487190][  T232] RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000005
[   18.487192][  T232] RBP: 00007fff4f496070 R08: 0000000000000000 R09: 0000000000000000
[   18.487194][  T232] R10: 0000000000000010 R11: 0000000000000293 R12: 00007fff4f496508
[   18.487196][  T232] R13: 0000000000000001 R14: 000000000054e030 R15: 0000000000000001
| [   18.498918][  T232] #PF: error_code(0x0002) - not-present page
| [   18.499174][  T232] PGD 4b99067 P4D 4b99067 PUD a6aa067 PMD 0
| [   18.499436][  T232] Oops: Oops: 0002 [#1] SMP KASAN
| [   18.500148][  T232] Tainted: [B]=BAD_PAGE
[   18.500300][  T232] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   18.500555][  T232] RIP: 0010:try_to_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072)
[   18.500827][  T232] Code: 00 41 89 c0 b8 01 00 00 00 45 85 c0 74 0f 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 be 08 00 00 00 48 89 df e8 7f 7f 81 00 <f0> 48 0f ba 2b 00 72 11 48 83 c4 10 31 c0 5b 5d 41 5c 41 5d 41 5e
All code
========
   0:	00 41 89             	add    %al,-0x77(%rcx)
   3:	c0 b8 01 00 00 00 45 	sarb   $0x45,0x1(%rax)
   a:	85 c0                	test   %eax,%eax
   c:	74 0f                	je     0x1d
   e:	48 83 c4 10          	add    $0x10,%rsp
  12:	5b                   	pop    %rbx
  13:	5d                   	pop    %rbp
  14:	41 5c                	pop    %r12
  16:	41 5d                	pop    %r13
  18:	41 5e                	pop    %r14
  1a:	41 5f                	pop    %r15
  1c:	c3                   	ret
  1d:	be 08 00 00 00       	mov    $0x8,%esi
  22:	48 89 df             	mov    %rbx,%rdi
  25:	e8 7f 7f 81 00       	call   0x817fa9
  2a:*	f0 48 0f ba 2b 00    	lock btsq $0x0,(%rbx)		<-- trapping instruction
  30:	72 11                	jb     0x43
  32:	48 83 c4 10          	add    $0x10,%rsp
  36:	31 c0                	xor    %eax,%eax
  38:	5b                   	pop    %rbx
  39:	5d                   	pop    %rbp
  3a:	41 5c                	pop    %r12
  3c:	41 5d                	pop    %r13
  3e:	41 5e                	pop    %r14

Code starting with the faulting instruction
===========================================
   0:	f0 48 0f ba 2b 00    	lock btsq $0x0,(%rbx)
   6:	72 11                	jb     0x19
   8:	48 83 c4 10          	add    $0x10,%rsp
   c:	31 c0                	xor    %eax,%eax
   e:	5b                   	pop    %rbx
   f:	5d                   	pop    %rbp
  10:	41 5c                	pop    %r12
  12:	41 5d                	pop    %r13
  14:	41 5e                	pop    %r14
[   18.501573][  T232] RSP: 0018:ffffc90000ae7900 EFLAGS: 00010046
[   18.501828][  T232] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff9883e90a
[   18.502146][  T232] RDX: fffffbfff394a0cd RSI: 0000000000000008 RDI: ffffffff9ca50660
[   18.502449][  T232] RBP: ffffc90000ae7968 R08: 0000000000000001 R09: fffffbfff394a0cc
[   18.502748][  T232] R10: ffffffff9ca50667 R11: ffffc90000ae73c0 R12: 0000000000000000
[   18.503060][  T232] R13: 0000000000000286 R14: ffff88800bf6c000 R15: dffffc0000000000
[   18.503377][  T232] FS:  00000000176633c0(0000) GS:ffff88809999b000(0000) knlGS:0000000000000000
[   18.503733][  T232] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   18.503999][  T232] CR2: 0000000000000000 CR3: 0000000004a4d005 CR4: 0000000000772ef0
[   18.504305][  T232] PKRU: 55555554
[   18.504467][  T232] Call Trace:
[   18.504624][  T232]  <TASK>
[   18.504730][  T232]  __cancel_work (kernel/workqueue.c:2161 kernel/workqueue.c:4364)
[   18.504946][  T232]  ? enable_delayed_work (kernel/workqueue.c:4359)
[   18.505156][  T232]  ? qdisc_destroy (net/sched/sch_generic.c:1355)
[   18.505374][  T232]  __cancel_work_sync (kernel/workqueue.c:4383)
[   18.505572][  T232]  __dev_close_many (net/core/dev.c:1879 (discriminator 2) net/core/dev.c:1932 (discriminator 2))
[   18.505774][  T232]  ? netdev_notify_peers (net/core/dev.c:1891)
[   18.505987][  T232]  ? netif_close_many (net/core/dev.c:1959)
[   18.506193][  T232]  netif_close_many (net/core/dev.c:1959)
[   18.506388][  T232]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[   18.506592][  T232]  ? __dev_close_many (net/core/dev.c:1949)
[   18.506788][  T232]  ? netif_close_many_and_unlock (net/core/dev.c:12476)
[   18.507039][  T232]  unregister_netdevice_many_notify (net/core/dev.c:12545)
[   18.507301][  T232]  ? sched_ttwu_pending (kernel/sched/core.c:4144)
[   18.507513][  T232]  ? dev_ingress_queue_create (net/core/dev.c:12499)
[   18.507710][  T232]  ? irqentry_exit (kernel/entry/common.c:215)
[   18.507918][  T232]  ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4472)
[   18.508135][  T232]  unregister_netdevice_queue (net/core/dev.c:12452)
[   18.508336][  T232]  ? unregister_netdevice_many (net/core/dev.c:12441)
[   18.508533][  T232]  ? queue_delayed_work_on (kernel/workqueue.c:2567)
[   18.508731][  T232]  __tun_detach (./include/linux/netdevice.h:3491 drivers/net/tun.c:621)
[   18.508944][  T232]  tun_chr_close (drivers/net/tun.c:638 drivers/net/tun.c:3436)
[   18.509149][  T232]  __fput (fs/file_table.c:468)
[   18.509314][  T232]  fput_close_sync (fs/file_table.c:571)
[   18.509520][  T232]  ? alloc_file_clone (fs/file_table.c:571)
[   18.509719][  T232]  __x64_sys_close (fs/open.c:1592 fs/open.c:1574 fs/open.c:1574)
[   18.509933][  T232]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[   18.510144][  T232]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   18.510402][  T232] RIP: 0033:0x4901eb
[   18.510569][  T232] 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
[   18.511297][  T232] RSP: 002b:00007fff4f496030 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
[   18.511602][  T232] RAX: ffffffffffffffda RBX: 00007fff4f496590 RCX: 00000000004901eb
[   18.511914][  T232] RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000005
[   18.512219][  T232] RBP: 00007fff4f496070 R08: 0000000000000000 R09: 0000000000000000
[   18.512522][  T232] R10: 0000000000000010 R11: 0000000000000293 R12: 00007fff4f496508


Finger prints:
kasan_report:kasan_check_range:try_to_grab_pending:__cancel_work:__cancel_work_sync
try_to_grab_pending:__cancel_work:__cancel_work_sync:__dev_close_many:netif_close_many