======================================
| [  242.979968][ T4765] ------------[ cut here ]------------
| [  242.980251][ T4765] refcount_t: decrement hit 0; leaking memory.
| [  242.980474][ T4765] WARNING: lib/refcount.c:31 at refcount_warn_saturate+0x59/0xc0, CPU#4: python3/4765
| [  242.980843][ T4765] Modules linked in: netdevsim
[  242.981666][ T4765] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  242.982056][ T4765] RIP: 0010:refcount_warn_saturate (lib/refcount.c:31 (discriminator 6))
[  242.982291][ T4765] Code: 07 83 c0 03 38 d0 7c 04 84 d2 75 75 c7 03 00 00 00 c0 83 fd 02 74 5b 76 19 83 fd 03 74 45 83 fd 04 75 22 48 8d 3d 97 b3 52 03 <67> 48 0f b9 3a 5b 5d c3 85 ed 74 1e 48 8d 3d 94 b3 52 03 67 48 0f
All code
========
   0:	07                   	(bad)
   1:	83 c0 03             	add    $0x3,%eax
   4:	38 d0                	cmp    %dl,%al
   6:	7c 04                	jl     0xc
   8:	84 d2                	test   %dl,%dl
   a:	75 75                	jne    0x81
   c:	c7 03 00 00 00 c0    	movl   $0xc0000000,(%rbx)
  12:	83 fd 02             	cmp    $0x2,%ebp
  15:	74 5b                	je     0x72
  17:	76 19                	jbe    0x32
  19:	83 fd 03             	cmp    $0x3,%ebp
  1c:	74 45                	je     0x63
  1e:	83 fd 04             	cmp    $0x4,%ebp
  21:	75 22                	jne    0x45
  23:	48 8d 3d 97 b3 52 03 	lea    0x352b397(%rip),%rdi        # 0x352b3c1
  2a:*	67 48 0f b9 3a       	ud1    (%edx),%rdi		<-- trapping instruction
  2f:	5b                   	pop    %rbx
  30:	5d                   	pop    %rbp
  31:	c3                   	ret
  32:	85 ed                	test   %ebp,%ebp
  34:	74 1e                	je     0x54
  36:	48 8d 3d 94 b3 52 03 	lea    0x352b394(%rip),%rdi        # 0x352b3d1
  3d:	67                   	addr32
  3e:	48                   	rex.W
  3f:	0f                   	.byte 0xf

Code starting with the faulting instruction
===========================================
   0:	67 48 0f b9 3a       	ud1    (%edx),%rdi
   5:	5b                   	pop    %rbx
   6:	5d                   	pop    %rbp
   7:	c3                   	ret
   8:	85 ed                	test   %ebp,%ebp
   a:	74 1e                	je     0x2a
   c:	48 8d 3d 94 b3 52 03 	lea    0x352b394(%rip),%rdi        # 0x352b3a7
  13:	67                   	addr32
  14:	48                   	rex.W
  15:	0f                   	.byte 0xf
[  242.982905][ T4765] RSP: 0018:ffa000000a96f508 EFLAGS: 00010246
[  242.983128][ T4765] RAX: 0000000000000003 RBX: ff1100002f1aa608 RCX: 0000000000000001
[  242.983395][ T4765] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8830c140
[  242.983648][ T4765] RBP: 0000000000000004 R08: ffffffff84de0d65 R09: 1fe2200005e354c1
[  242.983893][ T4765] R10: ffe21c0005e354c2 R11: ffe21c0005e354c2 R12: 1ff400000152dea8
[  242.984145][ T4765] R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000002
[  242.984395][ T4765] FS:  00007fed5cc82400(0000) GS:ff110000e36dd000(0000) knlGS:0000000000000000
[  242.984687][ T4765] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  242.984891][ T4765] CR2: 00007fed5c3c9160 CR3: 000000000a5cf006 CR4: 0000000000771ef0
[  242.985142][ T4765] PKRU: 55555554
[  242.985264][ T4765] Call Trace:
[  242.985385][ T4765]  <TASK>
[  242.985472][ T4765]  ref_tracker_free (./include/linux/refcount.h:461 ./include/linux/refcount.h:476 lib/ref_tracker.c:298)
[  242.985637][ T4765]  ? ref_tracker_alloc (lib/ref_tracker.c:288)
[  242.985800][ T4765]  ? kfree (mm/slub.c:6165 (discriminator 3) mm/slub.c:6483 (discriminator 3))
[  242.985924][ T4765]  udp_tunnel_nic_unregister (./include/linux/netdevice.h:4431 (discriminator 31) ./include/linux/netdevice.h:4492 (discriminator 31) ./include/linux/netdevice.h:4517 (discriminator 31) net/ipv4/udp_tunnel_nic.c:913 (discriminator 31))
[  242.986094][ T4765]  udp_tunnel_nic_netdevice_event (net/ipv4/udp_tunnel_nic.c:943)
[  242.986291][ T4765]  ? vxlan_dellink (drivers/net/vxlan/vxlan_core.c:4746)
[  242.986458][ T4765]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:752 (discriminator 3))
[  242.986619][ T4765]  notifier_call_chain (kernel/notifier.c:87)
[  242.986782][ T4765]  unregister_netdevice_many_notify (net/core/dev.c:12471)
[  242.986981][ T4765]  ? __mutex_lock (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3189 kernel/locking/mutex.c:88 kernel/locking/mutex.c:133 kernel/locking/mutex.c:617 kernel/locking/mutex.c:776)
[  242.987145][ T4765]  ? __mutex_lock (./arch/x86/include/asm/preempt.h:104 kernel/locking/mutex.c:755 kernel/locking/mutex.c:776)
[  242.987301][ T4765]  ? unregister_netdevice_queued (net/core/dev.c:12395)
[  242.987498][ T4765]  ? mark_held_locks (kernel/locking/lockdep.c:4325 (discriminator 1))
[  242.987659][ T4765]  ? nsim_destroy (drivers/net/netdevsim/netdev.c:1186 (discriminator 1)) netdevsim
[  242.987824][ T4765]  ? irqentry_enter (kernel/entry/common.c:169)
[  242.987986][ T4765]  unregister_netdevice_queue (net/core/dev.c:12344)
[  242.988155][ T4765]  ? unregister_netdevice_many (net/core/dev.c:12333)
[  242.988319][ T4765] nsim_destroy (drivers/net/netdevsim/netdev.c:1191) netdevsim
[  242.988485][ T4765]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:752 (discriminator 3))
[  242.988644][ T4765] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:444 drivers/net/netdevsim/dev.c:1548) netdevsim
[  242.988843][ T4765] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:1559 (discriminator 4) drivers/net/netdevsim/dev.c:1785 (discriminator 4)) netdevsim
[  242.989043][ T4765] nsim_drv_remove (drivers/net/netdevsim/dev.c:1802) netdevsim
[  242.989213][ T4765]  device_release_driver_internal (drivers/base/dd.c:1346 drivers/base/dd.c:1367)
[  242.989411][ T4765]  bus_remove_device (./include/linux/kobject.h:193 drivers/base/base.h:73 drivers/base/bus.c:664)
[  242.989573][ T4765]  ? bus_probe_device (drivers/base/bus.c:634)
[  242.989732][ T4765]  ? device_remove_file (drivers/base/core.c:2962)
[  242.989897][ T4765]  device_del (drivers/base/core.c:3881)
[  242.990016][ T4765]  ? __device_link_del (drivers/base/core.c:3835)
[  242.990180][ T4765]  ? sysfs_file_ops (fs/sysfs/file.c:135)
[  242.990340][ T4765]  device_unregister (drivers/base/core.c:3798 drivers/base/core.c:3922)
[  242.990498][ T4765] del_device_store (drivers/net/netdevsim/bus.c:248) netdevsim
[  242.990704][ T4765]  ? sysfs_file_kobj (./include/linux/rcupdate.h:322 (discriminator 2) ./include/linux/rcupdate.h:881 (discriminator 2) ./include/linux/rcupdate.h:1193 (discriminator 2) fs/sysfs/file.c:24 (discriminator 2))
[  242.990861][ T4765]  ? nsim_bus_dev_numvfs_show (drivers/net/netdevsim/bus.c:215) netdevsim
[  242.991070][ T4765]  ? sysfs_file_kobj (fs/sysfs/file.c:26)
[  242.991233][ T4765]  ? sysfs_kf_write (fs/sysfs/file.c:139)
[  242.991395][ T4765]  kernfs_fop_write_iter (fs/kernfs/file.c:88 fs/kernfs/file.c:356)
[  242.991556][ T4765]  ? kernfs_ops (fs/kernfs/file.c:312)
[  242.991676][ T4765]  new_sync_write (fs/read_write.c:596 (discriminator 1))
[  242.991839][ T4765]  ? __lock_acquire (kernel/locking/lockdep.c:5237)
[  242.991997][ T4765]  ? new_sync_read (fs/read_write.c:586)
[  242.992167][ T4765]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 (discriminator 2) kernel/locking/lockdep.c:5870 (discriminator 2))
[  242.992327][ T4765]  ? ksys_write (fs/read_write.c:741)
[  242.992492][ T4765]  vfs_write (fs/read_write.c:688)
[  242.992614][ T4765]  ksys_write (fs/read_write.c:741)
[  242.992735][ T4765]  ? __ia32_sys_read (fs/read_write.c:730)
[  242.992900][ T4765]  ? kernfs_fop_llseek (fs/kernfs/file.c:910)
[  242.993062][ T4765]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:752 (discriminator 3))
[  242.993226][ T4765]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[  242.993386][ T4765]  ? exc_page_fault (arch/x86/mm/fault.c:1480 (discriminator 3) arch/x86/mm/fault.c:1527 (discriminator 3))
[  242.993545][ T4765]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  242.993741][ T4765] RIP: 0033:0x7fed5ce0a22e
[  242.993916][ T4765] Code: 4d 89 d8 e8 94 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 03 ff ff ff 0f 1f 00 f3 0f 1e fa
All code
========
   0:	4d 89 d8             	mov    %r11,%r8
   3:	e8 94 bd 00 00       	call   0xbd9c
   8:	4c 8b 5d f8          	mov    -0x8(%rbp),%r11
   c:	41 8b 93 08 03 00 00 	mov    0x308(%r11),%edx
  13:	59                   	pop    %rcx
  14:	5e                   	pop    %rsi
  15:	48 83 f8 fc          	cmp    $0xfffffffffffffffc,%rax
  19:	74 11                	je     0x2c
  1b:	c9                   	leave
  1c:	c3                   	ret
  1d:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  24:	48 8b 45 10          	mov    0x10(%rbp),%rax
  28:	0f 05                	syscall
  2a:*	c9                   	leave		<-- trapping instruction
  2b:	c3                   	ret
  2c:	83 e2 39             	and    $0x39,%edx
  2f:	83 fa 08             	cmp    $0x8,%edx
  32:	75 e7                	jne    0x1b
  34:	e8 03 ff ff ff       	call   0xffffffffffffff3c
  39:	0f 1f 00             	nopl   (%rax)
  3c:	f3 0f 1e fa          	endbr64

Code starting with the faulting instruction
===========================================
   0:	c9                   	leave
   1:	c3                   	ret
   2:	83 e2 39             	and    $0x39,%edx
   5:	83 fa 08             	cmp    $0x8,%edx
   8:	75 e7                	jne    0xfffffffffffffff1
   a:	e8 03 ff ff ff       	call   0xffffffffffffff12
   f:	0f 1f 00             	nopl   (%rax)
  12:	f3 0f 1e fa          	endbr64
[  242.994488][ T4765] RSP: 002b:00007ffc45b7f160 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[  242.994730][ T4765] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fed5ce0a22e
[  242.994969][ T4765] RDX: 0000000000000004 RSI: 00005653d175ffa0 RDI: 0000000000000009
[  242.995212][ T4765] RBP: 00007ffc45b7f170 R08: 0000000000000000 R09: 0000000000000000
[  242.995456][ T4765] R10: 0000000000000000 R11: 0000000000000202 R12: 00007fed5cc82390
[  242.995698][ T4765] R13: 00005653d175ffa0 R14: 0000000000000009 R15: 0000000000000003
| [  243.019641][ T4765] ------------[ cut here ]------------
| [  243.019882][ T4765] WARNING: lib/ref_tracker.c:248 at ref_tracker_dir_exit+0x54f/0x7e0, CPU#4: python3/4765
| [  243.020153][ T4765] Modules linked in: netdevsim
| [  243.020656][ T4765] Tainted: [W]=WARN
[  243.020771][ T4765] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  243.021165][ T4765] RIP: 0010:ref_tracker_dir_exit (lib/ref_tracker.c:248 (discriminator 4))
[  243.021358][ T4765] Code: 00 00 00 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 8b 74 24 10 48 89 ef e8 50 03 62 01 e9 24 ff ff ff 90 0f 0b 90 e9 60 ff ff ff 90 <0f> 0b 90 eb 97 e8 07 61 84 ff e9 43 fb ff ff 48 89 df e8 9a 60 84
All code
========
   0:	00 00                	add    %al,(%rax)
   2:	00 5b 5d             	add    %bl,0x5d(%rbx)
   5:	41 5c                	pop    %r12
   7:	41 5d                	pop    %r13
   9:	41 5e                	pop    %r14
   b:	41 5f                	pop    %r15
   d:	c3                   	ret
   e:	48 8b 74 24 10       	mov    0x10(%rsp),%rsi
  13:	48 89 ef             	mov    %rbp,%rdi
  16:	e8 50 03 62 01       	call   0x162036b
  1b:	e9 24 ff ff ff       	jmp    0xffffffffffffff44
  20:	90                   	nop
  21:	0f 0b                	ud2
  23:	90                   	nop
  24:	e9 60 ff ff ff       	jmp    0xffffffffffffff89
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	eb 97                	jmp    0xffffffffffffffc6
  2f:	e8 07 61 84 ff       	call   0xffffffffff84613b
  34:	e9 43 fb ff ff       	jmp    0xfffffffffffffb7c
  39:	48 89 df             	mov    %rbx,%rdi
  3c:	e8                   	.byte 0xe8
  3d:	9a                   	(bad)
  3e:	60                   	(bad)
  3f:	84                   	.byte 0x84

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	eb 97                	jmp    0xffffffffffffff9c
   5:	e8 07 61 84 ff       	call   0xffffffffff846111
   a:	e9 43 fb ff ff       	jmp    0xfffffffffffffb52
   f:	48 89 df             	mov    %rbx,%rdi
  12:	e8                   	.byte 0xe8
  13:	9a                   	(bad)
  14:	60                   	(bad)
  15:	84                   	.byte 0x84
[  243.021892][ T4765] RSP: 0018:ffa000000a96f860 EFLAGS: 00010296
[  243.022078][ T4765] RAX: 0000000000000003 RBX: ff1100002f1aa608 RCX: 0000000000000001
[  243.022302][ T4765] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ff1100002f1aa608
[  243.022526][ T4765] RBP: ff1100002f1aa5c0 R08: ffffffff84efd55f R09: 1fe2200005e354c1
[  243.022747][ T4765] R10: ffe21c0005e354c2 R11: ffe21c0005e354c2 R12: ff1100002f1aa610
[  243.022966][ T4765] R13: dead000000000122 R14: dead000000000100 R15: dffffc0000000000
[  243.023191][ T4765] FS:  00007fed5cc82400(0000) GS:ff110000e36dd000(0000) knlGS:0000000000000000
[  243.023450][ T4765] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  243.023639][ T4765] CR2: 00007fed5c3c9160 CR3: 000000000a5cf006 CR4: 0000000000771ef0
[  243.023860][ T4765] PKRU: 55555554
[  243.023972][ T4765] Call Trace:
[  243.024089][ T4765]  <TASK>
[  243.024168][ T4765]  ? ref_tracker_free (lib/ref_tracker.c:220)
[  243.024316][ T4765]  ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473)
[  243.024465][ T4765]  ? kasan_quarantine_put (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:109 ./arch/x86/include/asm/irqflags.h:151 mm/kasan/quarantine.c:234)
[  243.024613][ T4765]  ? kfree (mm/slub.c:6165 (discriminator 3) mm/slub.c:6483 (discriminator 3))
[  243.024728][ T4765]  free_netdev (net/core/dev.c:12248)
[  243.024876][ T4765] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:444 drivers/net/netdevsim/dev.c:1548) netdevsim
[  243.025062][ T4765] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:1559 (discriminator 4) drivers/net/netdevsim/dev.c:1785 (discriminator 4)) netdevsim
[  243.025305][ T4765] nsim_drv_remove (drivers/net/netdevsim/dev.c:1802) netdevsim
[  243.025455][ T4765]  device_release_driver_internal (drivers/base/dd.c:1346 drivers/base/dd.c:1367)
[  243.025638][ T4765]  bus_remove_device (./include/linux/kobject.h:193 drivers/base/base.h:73 drivers/base/bus.c:664)
[  243.025783][ T4765]  ? bus_probe_device (drivers/base/bus.c:634)
[  243.025930][ T4765]  ? device_remove_file (drivers/base/core.c:2962)
[  243.026079][ T4765]  device_del (drivers/base/core.c:3881)
[  243.026246][ T4765]  ? __device_link_del (drivers/base/core.c:3835)
[  243.026393][ T4765]  ? sysfs_file_ops (fs/sysfs/file.c:135)
[  243.026541][ T4765]  device_unregister (drivers/base/core.c:3798 drivers/base/core.c:3922)
[  243.026685][ T4765] del_device_store (drivers/net/netdevsim/bus.c:248) netdevsim
[  243.026866][ T4765]  ? sysfs_file_kobj (./include/linux/rcupdate.h:322 (discriminator 2) ./include/linux/rcupdate.h:881 (discriminator 2) ./include/linux/rcupdate.h:1193 (discriminator 2) fs/sysfs/file.c:24 (discriminator 2))
[  243.027015][ T4765]  ? nsim_bus_dev_numvfs_show (drivers/net/netdevsim/bus.c:215) netdevsim
[  243.027254][ T4765]  ? sysfs_file_kobj (fs/sysfs/file.c:26)
[  243.027401][ T4765]  ? sysfs_kf_write (fs/sysfs/file.c:139)
[  243.027551][ T4765]  kernfs_fop_write_iter (fs/kernfs/file.c:88 fs/kernfs/file.c:356)
[  243.027697][ T4765]  ? kernfs_ops (fs/kernfs/file.c:312)
[  243.027807][ T4765]  new_sync_write (fs/read_write.c:596 (discriminator 1))
[  243.027953][ T4765]  ? __lock_acquire (kernel/locking/lockdep.c:5237)
[  243.028156][ T4765]  ? new_sync_read (fs/read_write.c:586)
[  243.028306][ T4765]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 (discriminator 2) kernel/locking/lockdep.c:5870 (discriminator 2))
[  243.028454][ T4765]  ? ksys_write (fs/read_write.c:741)
[  243.028604][ T4765]  vfs_write (fs/read_write.c:688)
[  243.028716][ T4765]  ksys_write (fs/read_write.c:741)
[  243.028826][ T4765]  ? __ia32_sys_read (fs/read_write.c:730)
[  243.028971][ T4765]  ? kernfs_fop_llseek (fs/kernfs/file.c:910)
[  243.029174][ T4765]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:752 (discriminator 3))
[  243.029321][ T4765]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[  243.029473][ T4765]  ? exc_page_fault (arch/x86/mm/fault.c:1480 (discriminator 3) arch/x86/mm/fault.c:1527 (discriminator 3))
[  243.029618][ T4765]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  243.029798][ T4765] RIP: 0033:0x7fed5ce0a22e
[  243.029953][ T4765] Code: 4d 89 d8 e8 94 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 03 ff ff ff 0f 1f 00 f3 0f 1e fa
All code
========
   0:	4d 89 d8             	mov    %r11,%r8
   3:	e8 94 bd 00 00       	call   0xbd9c
   8:	4c 8b 5d f8          	mov    -0x8(%rbp),%r11
   c:	41 8b 93 08 03 00 00 	mov    0x308(%r11),%edx
  13:	59                   	pop    %rcx
  14:	5e                   	pop    %rsi
  15:	48 83 f8 fc          	cmp    $0xfffffffffffffffc,%rax
  19:	74 11                	je     0x2c
  1b:	c9                   	leave
  1c:	c3                   	ret
  1d:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  24:	48 8b 45 10          	mov    0x10(%rbp),%rax
  28:	0f 05                	syscall
  2a:*	c9                   	leave		<-- trapping instruction
  2b:	c3                   	ret
  2c:	83 e2 39             	and    $0x39,%edx
  2f:	83 fa 08             	cmp    $0x8,%edx
  32:	75 e7                	jne    0x1b
  34:	e8 03 ff ff ff       	call   0xffffffffffffff3c
  39:	0f 1f 00             	nopl   (%rax)
  3c:	f3 0f 1e fa          	endbr64

Code starting with the faulting instruction
===========================================
   0:	c9                   	leave
   1:	c3                   	ret
   2:	83 e2 39             	and    $0x39,%edx
   5:	83 fa 08             	cmp    $0x8,%edx
   8:	75 e7                	jne    0xfffffffffffffff1
   a:	e8 03 ff ff ff       	call   0xffffffffffffff12
   f:	0f 1f 00             	nopl   (%rax)
  12:	f3 0f 1e fa          	endbr64
[  243.030541][ T4765] RSP: 002b:00007ffc45b7f160 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[  243.030760][ T4765] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fed5ce0a22e
[  243.030979][ T4765] RDX: 0000000000000004 RSI: 00005653d175ffa0 RDI: 0000000000000009
[  243.031257][ T4765] RBP: 00007ffc45b7f170 R08: 0000000000000000 R09: 0000000000000000
[  243.031479][ T4765] R10: 0000000000000000 R11: 0000000000000202 R12: 00007fed5cc82390
[  243.031698][ T4765] R13: 00005653d175ffa0 R14: 0000000000000009 R15: 0000000000000003
| [  249.175747][ T4765] refcount_t: saturated; leaking memory.
| [  249.175909][ T4765] WARNING: lib/refcount.c:22 at refcount_warn_saturate+0x6c/0xc0, CPU#0: python3/4765
| [  249.176486][ T4765] Modules linked in: netdevsim
| [  249.177009][ T4765] Tainted: [W]=WARN
[  249.177154][ T4765] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  249.177501][ T4765] RIP: 0010:refcount_warn_saturate (lib/refcount.c:22 (discriminator 6))
[  249.177699][ T4765] Code: fd 02 74 5b 76 19 83 fd 03 74 45 83 fd 04 75 22 48 8d 3d 97 b3 52 03 67 48 0f b9 3a 5b 5d c3 85 ed 74 1e 48 8d 3d 94 b3 52 03 <67> 48 0f b9 3a 5b 5d c3 48 8d 3d 95 b3 52 03 67 48 0f b9 3a 5b 5d
All code
========
   0:	fd                   	std
   1:	02 74 5b 76          	add    0x76(%rbx,%rbx,2),%dh
   5:	19 83 fd 03 74 45    	sbb    %eax,0x457403fd(%rbx)
   b:	83 fd 04             	cmp    $0x4,%ebp
   e:	75 22                	jne    0x32
  10:	48 8d 3d 97 b3 52 03 	lea    0x352b397(%rip),%rdi        # 0x352b3ae
  17:	67 48 0f b9 3a       	ud1    (%edx),%rdi
  1c:	5b                   	pop    %rbx
  1d:	5d                   	pop    %rbp
  1e:	c3                   	ret
  1f:	85 ed                	test   %ebp,%ebp
  21:	74 1e                	je     0x41
  23:	48 8d 3d 94 b3 52 03 	lea    0x352b394(%rip),%rdi        # 0x352b3be
  2a:*	67 48 0f b9 3a       	ud1    (%edx),%rdi		<-- trapping instruction
  2f:	5b                   	pop    %rbx
  30:	5d                   	pop    %rbp
  31:	c3                   	ret
  32:	48 8d 3d 95 b3 52 03 	lea    0x352b395(%rip),%rdi        # 0x352b3ce
  39:	67 48 0f b9 3a       	ud1    (%edx),%rdi
  3e:	5b                   	pop    %rbx
  3f:	5d                   	pop    %rbp

Code starting with the faulting instruction
===========================================
   0:	67 48 0f b9 3a       	ud1    (%edx),%rdi
   5:	5b                   	pop    %rbx
   6:	5d                   	pop    %rbp
   7:	c3                   	ret
   8:	48 8d 3d 95 b3 52 03 	lea    0x352b395(%rip),%rdi        # 0x352b3a4
   f:	67 48 0f b9 3a       	ud1    (%edx),%rdi
  14:	5b                   	pop    %rbx
  15:	5d                   	pop    %rbp
[  249.178238][ T4765] RSP: 0018:ffa000000a96f610 EFLAGS: 00010202
[  249.178424][ T4765] RAX: 0000000000000003 RBX: ff110000111b2608 RCX: 0000000000000001
[  249.178646][ T4765] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8830c150
[  249.178864][ T4765] RBP: 0000000000000001 R08: ffffffff84de0d65 R09: 1fe22000022364c1
[  249.179079][ T4765] R10: ffe21c00022364c2 R11: ffe21c00022364c2 R12: 1ff400000152dec6
[  249.179299][ T4765] R13: 0000000000000820 R14: 0000000000000000 R15: 0000000000000000
[  249.179517][ T4765] FS:  00007fed5cc82400(0000) GS:ff110000e34dd000(0000) knlGS:0000000000000000
[  249.179769][ T4765] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  249.179951][ T4765] CR2: 00007fed5c32e140 CR3: 000000000a5cf004 CR4: 0000000000771ef0
[  249.180170][ T4765] PKRU: 55555554
[  249.180277][ T4765] Call Trace:
[  249.180382][ T4765]  <TASK>
[  249.180456][ T4765]  ref_tracker_alloc (./include/linux/refcount.h:291 ./include/linux/refcount.h:366 ./include/linux/refcount.h:383 lib/ref_tracker.c:265)
[  249.180604][ T4765]  ? ref_tracker_dir_print (lib/ref_tracker.c:255)
[  249.180751][ T4765]  dev_get_by_index (./include/linux/rcupdate.h:879 net/core/dev.c:1003)
[  249.180896][ T4765]  netdev_get_by_index_lock_ops_compat (net/core/dev.c:1118)
[  249.181071][ T4765]  netdev_nl_queue_get_doit (net/core/netdev-genl.c:571 (discriminator 1))
[  249.181221][ T4765]  genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116)
[  249.181366][ T4765]  ? genl_family_rcv_msg_attrs_parse.isra.0 (net/netlink/genetlink.c:1087)
[  249.181546][ T4765]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 (discriminator 2) kernel/locking/lockdep.c:5870 (discriminator 2))
[  249.181690][ T4765]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[  249.181837][ T4765]  ? is_bpf_text_address (kernel/bpf/core.c:753)
[  249.181983][ T4765]  genl_family_rcv_msg (net/netlink/genetlink.c:1194 (discriminator 1))
[  249.182133][ T4765]  ? genl_family_rcv_msg_dumpit (net/netlink/genetlink.c:1159)
[  249.182306][ T4765]  ? rcu_lockdep_current_cpu_online (kernel/rcu/tree.c:4040 (discriminator 4) kernel/rcu/tree.c:4032 (discriminator 4))
[  249.182486][ T4765]  ? netdev_nl_napi_set_doit (net/core/netdev-genl.c:552)
[  249.182627][ T4765]  ? validate_chain (kernel/locking/lockdep.c:3801 (discriminator 3) kernel/locking/lockdep.c:3821 (discriminator 3) kernel/locking/lockdep.c:3876 (discriminator 3))
[  249.182766][ T4765]  ? __lock_acquire (kernel/locking/lockdep.c:5237)
[  249.182908][ T4765]  ? srcu_funnel_gp_start (kernel/rcu/srcutree.c:1089 (discriminator 1))
[  249.183050][ T4765]  genl_rcv_msg (net/netlink/genetlink.c:65 net/netlink/genetlink.c:1210)
[  249.183198][ T4765]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[  249.183338][ T4765]  ? genl_family_rcv_msg (net/netlink/genetlink.c:1200)
[  249.183482][ T4765]  ? netlink_ack (net/netlink/af_netlink.c:2527)
[  249.183627][ T4765]  ? netlink_deliver_tap (./include/linux/rcupdate.h:322 (discriminator 2) ./include/linux/rcupdate.h:881 (discriminator 2) ./include/net/netns/generic.h:48 (discriminator 2) net/netlink/af_netlink.c:333 (discriminator 2))
[  249.183767][ T4765]  ? netlink_deliver_tap (./include/linux/rcupdate.h:322 (discriminator 2) ./include/linux/rcupdate.h:881 (discriminator 2) net/netlink/af_netlink.c:340 (discriminator 2))
[  249.183911][ T4765]  genl_rcv (net/netlink/genetlink.c:1219)
[  249.184021][ T4765]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[  249.184169][ T4765]  ? netlink_attachskb (net/netlink/af_netlink.c:1329)
[  249.184310][ T4765]  ? __alloc_skb (./include/linux/bottom_half.h:20 (discriminator 2) net/core/skbuff.c:695 (discriminator 2))
[  249.184451][ T4765]  ? napi_skb_cache_get (net/core/skbuff.c:674)
[  249.184593][ T4765]  ? netlink_autobind.isra.0 (./include/linux/rcupdate.h:322 (discriminator 2) ./include/linux/rcupdate.h:881 (discriminator 2) net/netlink/af_netlink.c:814 (discriminator 2))
[  249.184734][ T4765]  ? netlink_autobind.isra.0 (net/netlink/af_netlink.c:827)
[  249.184877][ T4765]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[  249.185020][ T4765]  ? netlink_unicast (net/netlink/af_netlink.c:1813)
[  249.185165][ T4765]  ? _copy_from_user (./arch/x86/include/asm/smap.h:47 ./arch/x86/include/asm/uaccess_64.h:121 ./arch/x86/include/asm/uaccess_64.h:141 ./include/linux/uaccess.h:185 lib/usercopy.c:18)
[  249.185307][ T4765]  ? netlink_setsockopt (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 net/netlink/af_netlink.c:1714)
[  249.185449][ T4765]  __sys_sendto (net/socket.c:722 (discriminator 4) net/socket.c:737 (discriminator 4) net/socket.c:2200 (discriminator 4))
[  249.185593][ T4765]  ? __ia32_sys_getpeername (net/socket.c:2167)
[  249.185733][ T4765]  ? kfree (mm/slub.c:6471 (discriminator 1))
[  249.185844][ T4765]  ? put_user_ifreq (net/socket.c:2285)
[  249.185990][ T4765]  ? __sys_setsockopt (net/socket.c:2341 (discriminator 1))
[  249.186135][ T4765]  __x64_sys_sendto (net/socket.c:2207 (discriminator 1) net/socket.c:2203 (discriminator 1) net/socket.c:2203 (discriminator 1))
[  249.186276][ T4765]  ? trace_irq_enable.constprop.0 (./include/trace/events/preemptirq.h:40 (discriminator 24))
[  249.186450][ T4765]  ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473)
[  249.186594][ T4765]  ? do_syscall_64 (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:119 ./include/linux/entry-common.h:186 arch/x86/entry/syscall_64.c:90)
[  249.186735][ T4765]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[  249.186874][ T4765]  ? irq_exit_rcu (kernel/softirq.c:741 (discriminator 32))
[  249.187015][ T4765]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  249.187197][ T4765] RIP: 0033:0x7fed5ce0a22e
[  249.187348][ T4765] Code: 4d 89 d8 e8 94 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 03 ff ff ff 0f 1f 00 f3 0f 1e fa
All code
========
   0:	4d 89 d8             	mov    %r11,%r8
   3:	e8 94 bd 00 00       	call   0xbd9c
   8:	4c 8b 5d f8          	mov    -0x8(%rbp),%r11
   c:	41 8b 93 08 03 00 00 	mov    0x308(%r11),%edx
  13:	59                   	pop    %rcx
  14:	5e                   	pop    %rsi
  15:	48 83 f8 fc          	cmp    $0xfffffffffffffffc,%rax
  19:	74 11                	je     0x2c
  1b:	c9                   	leave
  1c:	c3                   	ret
  1d:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  24:	48 8b 45 10          	mov    0x10(%rbp),%rax
  28:	0f 05                	syscall
  2a:*	c9                   	leave		<-- trapping instruction
  2b:	c3                   	ret
  2c:	83 e2 39             	and    $0x39,%edx
  2f:	83 fa 08             	cmp    $0x8,%edx
  32:	75 e7                	jne    0x1b
  34:	e8 03 ff ff ff       	call   0xffffffffffffff3c
  39:	0f 1f 00             	nopl   (%rax)
  3c:	f3 0f 1e fa          	endbr64

Code starting with the faulting instruction
===========================================
   0:	c9                   	leave
   1:	c3                   	ret
   2:	83 e2 39             	and    $0x39,%edx
   5:	83 fa 08             	cmp    $0x8,%edx
   8:	75 e7                	jne    0xfffffffffffffff1
   a:	e8 03 ff ff ff       	call   0xffffffffffffff12
   f:	0f 1f 00             	nopl   (%rax)
  12:	f3 0f 1e fa          	endbr64
[  249.187849][ T4765] RSP: 002b:00007ffc45b7eeb0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
[  249.188066][ T4765] RAX: ffffffffffffffda RBX: 00007ffc45b7efc0 RCX: 00007fed5ce0a22e
[  249.188284][ T4765] RDX: 000000000000002c RSI: 00007fed5bfe0050 RDI: 000000000000000f
[  249.188496][ T4765] RBP: 00007ffc45b7eec0 R08: 0000000000000000 R09: 0000000000000000
[  249.188706][ T4765] R10: 0000000000000000 R11: 0000000000000202 R12: 00007fed5c0941a0


Finger prints:
ref_tracker_dir_exit:free_netdev:__nsim_dev_port_del:nsim_dev_reload_destroy:nsim_drv_remove
refcount_warn_saturate:ref_tracker_alloc:dev_get_by_index:netdev_get_by_index_lock_ops_compat:netdev_nl_queue_get_doit
refcount_warn_saturate:ref_tracker_free:udp_tunnel_nic_unregister:udp_tunnel_nic_netdevice_event:notifier_call_chain