======================================
| [    2.024498] ------------[ cut here ]------------
| [    2.024607] refcount_t: underflow; use-after-free.
| [    2.024679] WARNING: CPU: 2 PID: 237 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [    2.024755] Modules linked in: netdevsim
[    2.024883] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    2.024945] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[    2.025001] Code: 92 e8 88 98 ba ff 90 0f 0b 90 90 c3 80 3d 69 b4 eb 00 00 75 89 c6 05 60 b4 eb 00 01 90 48 c7 c7 98 6e 94 92 e8 65 98 ba ff 90 <0f> 0b 90 90 c3 80 3d 44 b4 eb 00 00 0f 85 62 ff ff ff c6 05 37 b4
All code
========
   0:	92                   	xchg   %eax,%edx
   1:	e8 88 98 ba ff       	call   0xffffffffffba988e
   6:	90                   	nop
   7:	0f 0b                	ud2
   9:	90                   	nop
   a:	90                   	nop
   b:	c3                   	ret
   c:	80 3d 69 b4 eb 00 00 	cmpb   $0x0,0xebb469(%rip)        # 0xebb47c
  13:	75 89                	jne    0xffffffffffffff9e
  15:	c6 05 60 b4 eb 00 01 	movb   $0x1,0xebb460(%rip)        # 0xebb47c
  1c:	90                   	nop
  1d:	48 c7 c7 98 6e 94 92 	mov    $0xffffffff92946e98,%rdi
  24:	e8 65 98 ba ff       	call   0xffffffffffba988e
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	c3                   	ret
  2f:	80 3d 44 b4 eb 00 00 	cmpb   $0x0,0xebb444(%rip)        # 0xebb47a
  36:	0f 85 62 ff ff ff    	jne    0xffffffffffffff9e
  3c:	c6                   	.byte 0xc6
  3d:	05                   	.byte 0x5
  3e:	37                   	(bad)
  3f:	b4                   	.byte 0xb4

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	c3                   	ret
   5:	80 3d 44 b4 eb 00 00 	cmpb   $0x0,0xebb444(%rip)        # 0xebb450
   c:	0f 85 62 ff ff ff    	jne    0xffffffffffffff74
  12:	c6                   	.byte 0xc6
  13:	05                   	.byte 0x5
  14:	37                   	(bad)
  15:	b4                   	.byte 0xb4
[    2.025131] RSP: 0018:ffffb2134029b730 EFLAGS: 00010282
[    2.025187] RAX: 0000000000000000 RBX: ffffb2134029b740 RCX: 00000000ffffdfff
[    2.025257] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[    2.025326] RBP: ffffb2134029b258 R08: ffffffff92d56a28 R09: 00000000ffffdfff
[    2.025395] R10: ffffffff92c76a40 R11: ffffffff92d26a40 R12: dead000000000122
[    2.025476] R13: 00000000fffb7387 R14: 0000000000000001 R15: ffff9e9802c9f000
[    2.025547] FS:  00007fcfd2e10800(0000) GS:ffff9e98ab8b7000(0000) knlGS:0000000000000000
[    2.025618] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.025680] CR2: 00007f1b452505f0 CR3: 0000000001fe0004 CR4: 0000000000772ef0
[    2.025749] PKRU: 55555554
[    2.025788] Call Trace:
[    2.025828]  <TASK>
[    2.025867]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    2.025921]  rtnl_dellink (net/core/rtnetlink.c:3580)
[    2.025972]  ? virtio_fs_enqueue_req (fs/fuse/virtio_fs.c:1473)
[    2.026034]  ? netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11653)
[    2.026085]  ? rtnl_bridge_getlink (net/core/rtnetlink.c:3536)
[    2.026140]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)
[    2.026191]  ? get_page_from_freelist (mm/page_alloc.c:1226 mm/page_alloc.c:1848 mm/page_alloc.c:1858 mm/page_alloc.c:3884)
[    2.026250]  ? rtnl_calcit.isra.0 (net/core/rtnetlink.c:6861)
[    2.026306]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[    2.026357]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[    2.026408]  ? __alloc_skb (net/core/skbuff.c:690)
[    2.026467]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[    2.026516]  ____sys_sendmsg (net/socket.c:727 net/socket.c:742 net/socket.c:2630)
[    2.026565]  ? copy_msghdr_from_user (net/socket.c:2570)
[    2.026622]  ___sys_sendmsg (net/socket.c:2686)
[    2.026672]  ? do_wp_page (./include/linux/mmu_notifier.h:468 mm/memory.c:3786 mm/memory.c:4140)
[    2.026722]  ? __handle_mm_fault (mm/memory.c:6193 mm/memory.c:6318)
[    2.026778]  ? fsnotify_grab_connector (fs/notify/mark.c:709)
[    2.026834]  ? fsnotify_destroy_marks (fs/notify/mark.c:937)
[    2.026889]  __sys_sendmsg (net/socket.c:2716)
[    2.026938]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    2.026986]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    2.027045] RIP: 0033:0x7fcfd2fde1d7
[    2.027094] 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)
[    2.027222] RSP: 002b:00007ffedffb4508 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[    2.027292] RAX: ffffffffffffffda RBX: 00007ffedffb4c30 RCX: 00007fcfd2fde1d7
[    2.027361] RDX: 0000000000000000 RSI: 00007ffedffb4570 RDI: 0000000000000005
[    2.027431] RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000078
[    2.027509] R10: 00007fcfd2edaf60 R11: 0000000000000246 R12: 0000000000000001
[    2.027578] R13: 00000000690df005 R14: 0000000000499600 R15: 0000000000000000
| [    2.375507] ------------[ cut here ]------------
| [    2.375649] kernel BUG at net/core/net-sysfs.c:2246!
| [    2.375701] Oops: invalid opcode: 0000 [#1] SMP
| [    2.375878] Tainted: [W]=WARN
[    2.375915] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    2.375980] RIP: 0010:netdev_release (net/core/net-sysfs.c:2246 net/core/net-sysfs.c:2242)
[    2.376036] Code: fa 0f 1f 44 00 00 80 7f e0 04 75 1d 55 48 8d af d0 fa ff ff 48 8b bf 00 fc ff ff e8 cd ff a3 ff 48 89 ef 5d e9 84 06 a4 ff 90 <0f> 0b 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 f5 48 8d 97 e8 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 d0 fa ff ff 	lea    -0x530(%rdi),%rbp
  14:	48 8b bf 00 fc ff ff 	mov    -0x400(%rdi),%rdi
  1b:	e8 cd ff a3 ff       	call   0xffffffffffa3ffed
  20:	48 89 ef             	mov    %rbp,%rdi
  23:	5d                   	pop    %rbp
  24:	e9 84 06 a4 ff       	jmp    0xffffffffffa406ad
  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:	e8                   	.byte 0xe8
  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:	e8                   	.byte 0xe8
  14:	fb                   	sti
  15:	ff                   	.byte 0xff
[    2.376210] RSP: 0018:ffffb213404ffbf0 EFLAGS: 00010297
[    2.376258] RAX: ffffffff9235a5d0 RBX: 00000000ffffffff RCX: 0000000000000002
[    2.376334] RDX: 0000000000000006 RSI: ffffffff92153ba4 RDI: ffff9e980194c530
[    2.376405] RBP: ffff9e980194c530 R08: 00000000000001d0 R09: 000000000000016d
[    2.376455] R10: 0000000000000180 R11: 0000000000000170 R12: ffff9e980272fa00
[    2.376504] R13: ffffffff926b1d20 R14: ffff9e9802e51b10 R15: ffff9e980194c000
[    2.376556] FS:  00007f17f5d0a000(0000) GS:ffff9e98ab837000(0000) knlGS:0000000000000000
[    2.376611] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.376658] CR2: 00005638908efa91 CR3: 0000000003a8b002 CR4: 0000000000772ef0
[    2.376708] PKRU: 55555554
[    2.376729] Call Trace:
[    2.376748]  <TASK>
[    2.376767]  device_release (drivers/base/core.c:2569)
[    2.376800]  kobject_put (lib/kobject.c:693 lib/kobject.c:720 ./include/linux/kref.h:65 lib/kobject.c:737)
[    2.376832]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    2.376870] nsim_destroy (drivers/net/netdevsim/netdevsim.h:396 drivers/net/netdevsim/netdev.c:1186) netdevsim
[    2.376922] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:441 drivers/net/netdevsim/dev.c:1474) netdevsim
[    2.376962] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:1483 drivers/net/netdevsim/dev.c:1707) netdevsim
[    2.377002] nsim_drv_remove (drivers/net/netdevsim/dev.c:1724) netdevsim
[    2.377041]  device_release_driver_internal (drivers/base/dd.c:1276 drivers/base/dd.c:1297)
[    2.377080]  bus_remove_device (./include/linux/kobject.h:193 (discriminator 3) drivers/base/base.h:73 (discriminator 3) drivers/base/bus.c:586 (discriminator 3))
[    2.377112]  device_del (drivers/base/core.c:3879)
[    2.377142]  device_unregister (drivers/base/core.c:3796 drivers/base/core.c:3920)
[    2.377172] del_device_store (drivers/net/netdevsim/bus.c:248) netdevsim
[    2.377210]  kernfs_fop_write_iter (fs/kernfs/file.c:88 fs/kernfs/file.c:356)
[    2.377250]  vfs_write (fs/read_write.c:594 fs/read_write.c:686)
[    2.377285]  ksys_write (fs/read_write.c:738)
[    2.377315]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    2.377346]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    2.377383] RIP: 0033:0x7f17f5e0a257
[    2.377408] Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
All code
========
   0:	0f 00                	(bad)
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b7                	jmp    0xffffffffffffffc7
  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 01 00 00 00       	mov    $0x1,%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:	48 89 54 24 18       	mov    %rdx,0x18(%rsp)
  3c:	48                   	rex.W
  3d:	89                   	.byte 0x89
  3e:	74 24                	je     0x64

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:	48 89 54 24 18       	mov    %rdx,0x18(%rsp)
  12:	48                   	rex.W
  13:	89                   	.byte 0x89
  14:	74 24                	je     0x3a
[    2.377529] RSP: 002b:00007ffe8b946d48 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[    2.377583] RAX: ffffffffffffffda RBX: 00007f17f5f06780 RCX: 00007f17f5e0a257
[    2.377632] RDX: 0000000000000004 RSI: 00005638908efa90 RDI: 0000000000000001
[    2.377683] RBP: 0000000000000004 R08: 0000000000000000 R09: 00007f17f5ebcd20
[    2.377731] R10: 00007f17f5ebcc20 R11: 0000000000000246 R12: 0000000000000004


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