======================================
| [    2.515951] ------------[ cut here ]------------
| [    2.516091] refcount_t: underflow; use-after-free.
| [    2.516177] WARNING: CPU: 2 PID: 321 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [    2.516298] Modules linked in: geneve vxlan ip6_udp_tunnel udp_tunnel netdevsim
[    2.516490] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    2.516554] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[    2.516611] Code: 9d e8 e8 de ba ff 90 0f 0b 90 90 c3 80 3d 09 da eb 00 00 75 89 c6 05 00 da eb 00 01 90 48 c7 c7 20 33 d3 9d e8 c5 de ba ff 90 <0f> 0b 90 90 c3 80 3d e4 d9 eb 00 00 0f 85 62 ff ff ff c6 05 d7 d9
All code
========
   0:	9d                   	popf
   1:	e8 e8 de ba ff       	call   0xffffffffffbadeee
   6:	90                   	nop
   7:	0f 0b                	ud2
   9:	90                   	nop
   a:	90                   	nop
   b:	c3                   	ret
   c:	80 3d 09 da eb 00 00 	cmpb   $0x0,0xebda09(%rip)        # 0xebda1c
  13:	75 89                	jne    0xffffffffffffff9e
  15:	c6 05 00 da eb 00 01 	movb   $0x1,0xebda00(%rip)        # 0xebda1c
  1c:	90                   	nop
  1d:	48 c7 c7 20 33 d3 9d 	mov    $0xffffffff9dd33320,%rdi
  24:	e8 c5 de ba ff       	call   0xffffffffffbadeee
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	c3                   	ret
  2f:	80 3d e4 d9 eb 00 00 	cmpb   $0x0,0xebd9e4(%rip)        # 0xebda1a
  36:	0f 85 62 ff ff ff    	jne    0xffffffffffffff9e
  3c:	c6                   	.byte 0xc6
  3d:	05                   	.byte 0x5
  3e:	d7                   	xlat   %ds:(%rbx)
  3f:	d9                   	.byte 0xd9

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	c3                   	ret
   5:	80 3d e4 d9 eb 00 00 	cmpb   $0x0,0xebd9e4(%rip)        # 0xebd9f0
   c:	0f 85 62 ff ff ff    	jne    0xffffffffffffff74
  12:	c6                   	.byte 0xc6
  13:	05                   	.byte 0x5
  14:	d7                   	xlat   %ds:(%rbx)
  15:	d9                   	.byte 0xd9
[    2.516782] RSP: 0018:ffffaf00004bf730 EFLAGS: 00010282
[    2.516894] RAX: 0000000000000000 RBX: ffffaf00004bf740 RCX: 00000000ffffdfff
[    2.517001] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[    2.517102] RBP: ffffaf00004bf268 R08: ffffffff9e156a28 R09: 00000000ffffdfff
[    2.517197] R10: ffffffff9e076a40 R11: ffffffff9e126a40 R12: dead000000000122
[    2.517293] R13: 00000000fffb7573 R14: 0000000000000001 R15: ffff9303c2c3f000
[    2.517378] FS:  00007fa34affc800(0000) GS:ffff9304604d9000(0000) knlGS:0000000000000000
[    2.517461] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.517530] CR2: 0000561dbb08b148 CR3: 000000000652b003 CR4: 0000000000772ef0
[    2.517617] PKRU: 55555554
[    2.517664] Call Trace:
[    2.517712]  <TASK>
[    2.517762]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    2.517827]  rtnl_dellink (net/core/rtnetlink.c:3580)
[    2.517905]  ? virtio_fs_enqueue_req (fs/fuse/virtio_fs.c:1473)
[    2.517984]  ? netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11653)
[    2.518051]  ? rtnl_bridge_getlink (net/core/rtnetlink.c:3536)
[    2.518126]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)
[    2.518190]  ? get_page_from_freelist (mm/page_alloc.c:1226 mm/page_alloc.c:1848 mm/page_alloc.c:1858 mm/page_alloc.c:3884)
[    2.518268]  ? rtnl_calcit.isra.0 (net/core/rtnetlink.c:6861)
[    2.518339]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[    2.518408]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[    2.518466]  ? __alloc_skb (net/core/skbuff.c:690)
[    2.518530]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[    2.518589]  ____sys_sendmsg (net/socket.c:727 net/socket.c:742 net/socket.c:2630)
[    2.518657]  ? copy_msghdr_from_user (net/socket.c:2570)
[    2.518723]  ___sys_sendmsg (net/socket.c:2686)
[    2.518783]  ? do_wp_page (./include/linux/mmu_notifier.h:468 mm/memory.c:3786 mm/memory.c:4140)
[    2.518846]  ? ___pte_offset_map (./include/linux/pgtable.h:347 ./include/linux/pgtable.h:635 mm/pgtable-generic.c:288)
[    2.518921]  ? __handle_mm_fault (mm/memory.c:6193 mm/memory.c:6318)
[    2.518984]  ? fsnotify_grab_connector (fs/notify/mark.c:709)
[    2.519049]  ? fsnotify_destroy_marks (fs/notify/mark.c:937)
[    2.519159]  __sys_sendmsg (net/socket.c:2716)
[    2.519214]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    2.519272]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    2.519336] RIP: 0033:0x7fa34b1ca1d7
[    2.519393] Code: 0e 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
All code
========
   0:	0e                   	(bad)
   1:	00 f7                	add    %dh,%bh
   3:	d8 64 89 02          	fsubs  0x2(%rcx,%rcx,4)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b9                	jmp    0xffffffffffffffc9
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 2e 00 00 00       	mov    $0x2e,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  3b:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  11:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)
[    2.519525] RSP: 002b:00007ffcb60f4378 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[    2.519596] RAX: ffffffffffffffda RBX: 00007ffcb60f4aa0 RCX: 00007fa34b1ca1d7
[    2.519670] RDX: 0000000000000000 RSI: 00007ffcb60f43e0 RDI: 0000000000000005
[    2.519740] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[    2.519819] R10: 00007fa34b0c6f60 R11: 0000000000000246 R12: 0000000000000002
[    2.519903] R13: 00000000690de69c R14: 0000000000499600 R15: 0000000000000000
| [    3.656964] ------------[ cut here ]------------
| [    3.657152] kernel BUG at net/core/net-sysfs.c:2246!
| [    3.657272] Oops: invalid opcode: 0000 [#1] SMP
| [    3.657390] Tainted: [W]=WARN
[    3.657418] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    3.657463] RIP: 0010:netdev_release (net/core/net-sysfs.c:2246 net/core/net-sysfs.c:2242)
[    3.657510] Code: fa 0f 1f 44 00 00 80 7f e0 04 75 1d 55 48 8d af e0 fa ff ff 48 8b bf 10 fc ff ff e8 6d 99 a6 ff 48 89 ef 5d e9 24 a0 a6 ff 90 <0f> 0b 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 f5 48 8d 97 f8 fb ff
All code
========
   0:	fa                   	cli
   1:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   6:	80 7f e0 04          	cmpb   $0x4,-0x20(%rdi)
   a:	75 1d                	jne    0x29
   c:	55                   	push   %rbp
   d:	48 8d af e0 fa ff ff 	lea    -0x520(%rdi),%rbp
  14:	48 8b bf 10 fc ff ff 	mov    -0x3f0(%rdi),%rdi
  1b:	e8 6d 99 a6 ff       	call   0xffffffffffa6998d
  20:	48 89 ef             	mov    %rbp,%rdi
  23:	5d                   	pop    %rbp
  24:	e9 24 a0 a6 ff       	jmp    0xffffffffffa6a04d
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	f3 0f 1e fa          	endbr64
  31:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  36:	55                   	push   %rbp
  37:	48 89 f5             	mov    %rsi,%rbp
  3a:	48                   	rex.W
  3b:	8d                   	.byte 0x8d
  3c:	97                   	xchg   %eax,%edi
  3d:	f8                   	clc
  3e:	fb                   	sti
  3f:	ff                   	.byte 0xff

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	f3 0f 1e fa          	endbr64
   7:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   c:	55                   	push   %rbp
   d:	48 89 f5             	mov    %rsi,%rbp
  10:	48                   	rex.W
  11:	8d                   	.byte 0x8d
  12:	97                   	xchg   %eax,%edi
  13:	f8                   	clc
  14:	fb                   	sti
  15:	ff                   	.byte 0xff
[    3.657641] RSP: 0018:ffffaf00002cbc70 EFLAGS: 00010297
[    3.657678] RAX: ffffffff9d730c30 RBX: 00000000ffffffff RCX: 0000000000000004
[    3.657738] RDX: 0000000000000008 RSI: ffffffff9d54f524 RDI: ffff9303c313c520
[    3.657806] RBP: ffff9303c313c520 R08: 0000000000000010 R09: 0000000000000018
[    3.657870] R10: 0000000000000400 R11: 0000000000000020 R12: ffff9303c5ebf200
[    3.657939] R13: ffffffff9dab1420 R14: ffff9303c2f26560 R15: ffff9303c313c000
[    3.658009] FS:  00007ff1ba5b4740(0000) GS:ffff9304604d9000(0000) knlGS:0000000000000000
[    3.658078] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    3.658144] CR2: 00007ff1ba61f12f CR3: 0000000005c42005 CR4: 0000000000772ef0
[    3.658225] PKRU: 55555554
[    3.658273] Call Trace:
[    3.658300]  <TASK>
[    3.658328]  device_release (drivers/base/core.c:2569)
[    3.658383]  kobject_put (lib/kobject.c:693 lib/kobject.c:720 ./include/linux/kref.h:65 lib/kobject.c:737)
[    3.658430]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    3.658482] nsim_destroy (drivers/net/netdevsim/netdevsim.h:396 drivers/net/netdevsim/netdev.c:1186) netdevsim
[    3.658545] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:441 drivers/net/netdevsim/dev.c:1474) netdevsim
[    3.658607] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:1483 drivers/net/netdevsim/dev.c:1707) netdevsim
[    3.658664] nsim_drv_remove (drivers/net/netdevsim/dev.c:1724) netdevsim
[    3.658722]  device_release_driver_internal (drivers/base/dd.c:1276 drivers/base/dd.c:1297)
[    3.658783]  bus_remove_device (./include/linux/kobject.h:193 (discriminator 3) drivers/base/base.h:73 (discriminator 3) drivers/base/bus.c:586 (discriminator 3))
[    3.658824]  device_del (drivers/base/core.c:3879)
[    3.658869]  device_unregister (drivers/base/core.c:3796 drivers/base/core.c:3920)
[    3.658915] nsim_bus_exit (drivers/net/netdevsim/bus.c:522 (discriminator 3)) netdevsim
[    3.658967] nsim_module_exit (drivers/net/netdevsim/netdev.c:184) netdevsim
[    3.659026]  __do_sys_delete_module (kernel/module/main.c:836)
[    3.659086]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    3.659136]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    3.659196] RIP: 0033:0x7ff1ba6e36eb
[    3.659236] Code: 73 01 c3 48 8b 0d 0d 97 0e 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d dd 96 0e 00 f7 d8 64 89 01 48
All code
========
   0:	73 01                	jae    0x3
   2:	c3                   	ret
   3:	48 8b 0d 0d 97 0e 00 	mov    0xe970d(%rip),%rcx        # 0xe9717
   a:	f7 d8                	neg    %eax
   c:	64 89 01             	mov    %eax,%fs:(%rcx)
   f:	48 83 c8 ff          	or     $0xffffffffffffffff,%rax
  13:	c3                   	ret
  14:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  1b:	00 00 00 
  1e:	90                   	nop
  1f:	f3 0f 1e fa          	endbr64
  23:	b8 b0 00 00 00       	mov    $0xb0,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax		<-- trapping instruction
  30:	73 01                	jae    0x33
  32:	c3                   	ret
  33:	48 8b 0d dd 96 0e 00 	mov    0xe96dd(%rip),%rcx        # 0xe9717
  3a:	f7 d8                	neg    %eax
  3c:	64 89 01             	mov    %eax,%fs:(%rcx)
  3f:	48                   	rex.W

Code starting with the faulting instruction
===========================================
   0:	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax
   6:	73 01                	jae    0x9
   8:	c3                   	ret
   9:	48 8b 0d dd 96 0e 00 	mov    0xe96dd(%rip),%rcx        # 0xe96ed
  10:	f7 d8                	neg    %eax
  12:	64 89 01             	mov    %eax,%fs:(%rcx)
  15:	48                   	rex.W
[    3.659415] RSP: 002b:00007fff724f2cd8 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[    3.659488] RAX: ffffffffffffffda RBX: 000056550ff5e960 RCX: 00007ff1ba6e36eb
[    3.659571] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000056550ff5e9c8
[    3.659649] RBP: 000056550ff5e960 R08: 0000000000000000 R09: 0000000000000000
[    3.659726] R10: 00007ff1ba772ac0 R11: 0000000000000206 R12: 000056550ff5e9c8


Finger prints:
netdev_release:device_release:kobject_put:netdev_run_todo:nsim_destroy
refcount_warn_saturate:netdev_run_todo:rtnl_dellink:rtnetlink_rcv_msg:netlink_rcv_skb