======================================
| [   16.257370][  T233] ==================================================================
| [   16.257879][  T233] 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)
| [   16.258338][  T233] Write of size 8 at addr 0000000000000000 by task packetdrill/233
| [   16.258768][  T233]
[   16.258925][  T233] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.258928][  T233] Call Trace:
[   16.258931][  T233]  <TASK>
[   16.258934][  T233]  dump_stack_lvl (lib/dump_stack.c:123)
[   16.258945][  T233]  ? try_to_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072)
[   16.258950][  T233]  kasan_report (mm/kasan/report.c:597)
[   16.258959][  T233]  ? try_to_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072)
[   16.258968][  T233]  kasan_check_range (mm/kasan/generic.c:194 mm/kasan/generic.c:200)
[   16.258975][  T233]  try_to_grab_pending (./arch/x86/include/asm/bitops.h:136 ./include/asm-generic/bitops/instrumented-atomic.h:72 kernel/workqueue.c:2072)
[   16.258983][  T233]  __cancel_work (kernel/workqueue.c:2161 kernel/workqueue.c:4364)
[   16.258989][  T233]  ? enable_delayed_work (kernel/workqueue.c:4359)
[   16.258997][  T233]  ? qdisc_destroy (net/sched/sch_generic.c:1355)
[   16.259008][  T233]  __cancel_work_sync (kernel/workqueue.c:4383)
[   16.259015][  T233]  __dev_close_many (net/core/dev.c:1879 (discriminator 2) net/core/dev.c:1932 (discriminator 2))
[   16.259022][  T233]  ? netdev_notify_peers (net/core/dev.c:1891)
[   16.259028][  T233]  ? netif_close_many (net/core/dev.c:1959)
[   16.259036][  T233]  netif_close_many (net/core/dev.c:1959)
[   16.259043][  T233]  ? __dev_close_many (net/core/dev.c:1949)
[   16.259049][  T233]  ? netif_close_many_and_unlock (net/core/dev.c:12476)
[   16.259057][  T233]  unregister_netdevice_many_notify (net/core/dev.c:12545)
[   16.259065][  T233]  ? try_to_wake_up (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:470 kernel/sched/core.c:4145)
[   16.259074][  T233]  ? sched_ttwu_pending (kernel/sched/core.c:4144)
[   16.259080][  T233]  ? dev_ingress_queue_create (net/core/dev.c:12499)
[   16.259085][  T233]  ? find_held_lock (kernel/locking/lockdep.c:5350)
[   16.259092][  T233]  ? __queue_work (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:897 kernel/workqueue.c:2350)
[   16.259097][  T233]  ? __lock_release (kernel/locking/lockdep.c:5536)
[   16.259104][  T233]  ? __queue_work (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:897 kernel/workqueue.c:2350)
[   16.259111][  T233]  unregister_netdevice_queue (net/core/dev.c:12452)
[   16.259118][  T233]  ? unregister_netdevice_many (net/core/dev.c:12441)
[   16.259125][  T233]  ? queue_delayed_work_on (kernel/workqueue.c:2565 (discriminator 1))
[   16.259130][  T233]  ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4472)
[   16.259140][  T233]  __tun_detach (./include/linux/netdevice.h:3491 drivers/net/tun.c:621)
[   16.259152][  T233]  tun_chr_close (drivers/net/tun.c:638 drivers/net/tun.c:3436)
[   16.259159][  T233]  __fput (fs/file_table.c:468)
[   16.259171][  T233]  fput_close_sync (fs/file_table.c:571)
[   16.259177][  T233]  ? alloc_file_clone (fs/file_table.c:571)
[   16.259186][  T233]  __x64_sys_close (fs/open.c:1592 fs/open.c:1574 fs/open.c:1574)
[   16.259192][  T233]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[   16.259201][  T233]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   16.259208][  T233] RIP: 0033:0x4901eb
[   16.259214][  T233] 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
[   16.259219][  T233] RSP: 002b:00007ffeb85df160 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
[   16.259226][  T233] RAX: ffffffffffffffda RBX: 00007ffeb85df6c0 RCX: 00000000004901eb
[   16.259229][  T233] RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000005
[   16.259232][  T233] RBP: 00007ffeb85df1a0 R08: 0000000000000000 R09: 0000000000000000
[   16.259235][  T233] R10: 0000000002000000 R11: 0000000000000293 R12: 00007ffeb85df638
[   16.259239][  T233] R13: 0000000000000001 R14: 000000000054e030 R15: 0000000000000001
| [   16.275493][  T233] #PF: error_code(0x0002) - not-present page
| [   16.275853][  T233] PGD c4e7067 P4D c4e7067 PUD c4e0067 PMD 0
| [   16.276201][  T233] Oops: Oops: 0002 [#1] SMP KASAN
| [   16.277121][  T233] Tainted: [B]=BAD_PAGE
[   16.277344][  T233] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.277696][  T233] 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)
[   16.278065][  T233] 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
[   16.279019][  T233] RSP: 0018:ffffc90000b57900 EFLAGS: 00010046
[   16.279363][  T233] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8f23e90a
[   16.279759][  T233] RDX: fffffbfff268a0cd RSI: 0000000000000008 RDI: ffffffff93450660
[   16.280159][  T233] RBP: ffffc90000b57968 R08: 0000000000000001 R09: fffffbfff268a0cc
[   16.280587][  T233] R10: ffffffff93450667 R11: ffffc90000b573c0 R12: 0000000000000000
[   16.280974][  T233] R13: 0000000000000286 R14: ffff88800ac4c000 R15: dffffc0000000000
[   16.281368][  T233] FS:  0000000022beb3c0(0000) GS:ffff88809d39b000(0000) knlGS:0000000000000000
[   16.281835][  T233] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   16.282170][  T233] CR2: 0000000000000000 CR3: 000000000a3c3001 CR4: 0000000000772ef0
[   16.282570][  T233] PKRU: 55555554
[   16.282780][  T233] Call Trace:
[   16.282994][  T233]  <TASK>
[   16.283158][  T233]  __cancel_work (kernel/workqueue.c:2161 kernel/workqueue.c:4364)
[   16.283453][  T233]  ? enable_delayed_work (kernel/workqueue.c:4359)
[   16.283745][  T233]  ? qdisc_destroy (net/sched/sch_generic.c:1355)
[   16.284028][  T233]  __cancel_work_sync (kernel/workqueue.c:4383)
[   16.284227][  T233]  __dev_close_many (net/core/dev.c:1879 (discriminator 2) net/core/dev.c:1932 (discriminator 2))
[   16.284403][  T233]  ? netdev_notify_peers (net/core/dev.c:1891)
[   16.284578][  T233]  ? netif_close_many (net/core/dev.c:1959)
[   16.284753][  T233]  netif_close_many (net/core/dev.c:1959)
[   16.284931][  T233]  ? __dev_close_many (net/core/dev.c:1949)
[   16.285134][  T233]  ? netif_close_many_and_unlock (net/core/dev.c:12476)
[   16.285355][  T233]  unregister_netdevice_many_notify (net/core/dev.c:12545)
[   16.285652][  T233]  ? try_to_wake_up (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:470 kernel/sched/core.c:4145)
[   16.285933][  T233]  ? sched_ttwu_pending (kernel/sched/core.c:4144)
[   16.286213][  T233]  ? dev_ingress_queue_create (net/core/dev.c:12499)
[   16.286490][  T233]  ? find_held_lock (kernel/locking/lockdep.c:5350)
[   16.286750][  T233]  ? __queue_work (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:897 kernel/workqueue.c:2350)
[   16.287027][  T233]  ? __lock_release (kernel/locking/lockdep.c:5536)
[   16.287306][  T233]  ? __queue_work (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:897 kernel/workqueue.c:2350)
[   16.287587][  T233]  unregister_netdevice_queue (net/core/dev.c:12452)
[   16.287854][  T233]  ? unregister_netdevice_many (net/core/dev.c:12441)
[   16.288135][  T233]  ? queue_delayed_work_on (kernel/workqueue.c:2565 (discriminator 1))
[   16.288415][  T233]  ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4472)
[   16.288696][  T233]  __tun_detach (./include/linux/netdevice.h:3491 drivers/net/tun.c:621)
[   16.288949][  T233]  tun_chr_close (drivers/net/tun.c:638 drivers/net/tun.c:3436)
[   16.289233][  T233]  __fput (fs/file_table.c:468)
[   16.289460][  T233]  fput_close_sync (fs/file_table.c:571)
[   16.289737][  T233]  ? alloc_file_clone (fs/file_table.c:571)
[   16.290021][  T233]  __x64_sys_close (fs/open.c:1592 fs/open.c:1574 fs/open.c:1574)
[   16.290301][  T233]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[   16.290582][  T233]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   16.290937][  T233] RIP: 0033:0x4901eb
[   16.291162][  T233] 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
[   16.292191][  T233] RSP: 002b:00007ffeb85df160 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
[   16.292622][  T233] RAX: ffffffffffffffda RBX: 00007ffeb85df6c0 RCX: 00000000004901eb
[   16.293039][  T233] RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000005
[   16.293415][  T233] RBP: 00007ffeb85df1a0 R08: 0000000000000000 R09: 0000000000000000
[   16.293823][  T233] R10: 0000000002000000 R11: 0000000000000293 R12: 00007ffeb85df638


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