======================================
| [    4.402965] ------------[ cut here ]------------
| [    4.403142] refcount_t: underflow; use-after-free.
| [    4.403231] WARNING: CPU: 2 PID: 351 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [    4.403334] Modules linked in: netconsole netdevsim
[    4.403517] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    4.403599] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[    4.403675] Code: b0 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 54 b0 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:	b0 e8                	mov    $0xe8,%al
   2:	88 98 ba ff 90 0f    	mov    %bl,0xf90ffba(%rax)
   8:	0b 90 90 c3 80 3d    	or     0x3d80c390(%rax),%edx
   e:	69 b4 eb 00 00 75 89 	imul   $0xb46005c6,-0x768b0000(%rbx,%rbp,8),%esi
  15:	c6 05 60 b4 
  19:	eb 00                	jmp    0x1b
  1b:	01 90 48 c7 c7 98    	add    %edx,-0x673838b8(%rax)
  21:	6e                   	outsb  %ds:(%rsi),(%dx)
  22:	54                   	push   %rsp
  23:	b0 e8                	mov    $0xe8,%al
  25:	65 98                	gs cwtl
  27:*	ba ff 90 0f 0b       	mov    $0xb0f90ff,%edx		<-- 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
[    4.403897] RSP: 0018:ffff9985c06cf730 EFLAGS: 00010282
[    4.403975] RAX: 0000000000000000 RBX: ffff9985c06cf740 RCX: 00000000ffffdfff
[    4.404076] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[    4.404176] RBP: ffff9985c06cf258 R08: ffffffffb0956a28 R09: 00000000ffffdfff
[    4.404277] R10: ffffffffb0876a40 R11: ffffffffb0926a40 R12: dead000000000122
[    4.404371] R13: 00000000fffb7cd0 R14: 0000000000000001 R15: ffff8d7282036000
[    4.404470] FS:  00007fbedcacb800(0000) GS:ffff8d730dcb7000(0000) knlGS:0000000000000000
[    4.404566] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.404648] CR2: 00000000004a1778 CR3: 000000000889c006 CR4: 0000000000772ef0
[    4.404746] PKRU: 55555554
[    4.404795] Call Trace:
[    4.404849]  <TASK>
[    4.404897]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    4.404965]  rtnl_dellink (net/core/rtnetlink.c:3580)
[    4.405036]  ? rtnl_bridge_getlink (net/core/rtnetlink.c:3536)
[    4.405109]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)
[    4.405177]  ? get_page_from_freelist (mm/page_alloc.c:1226 mm/page_alloc.c:1848 mm/page_alloc.c:1858 mm/page_alloc.c:3884)
[    4.405259]  ? rtnl_calcit.isra.0 (net/core/rtnetlink.c:6861)
[    4.405342]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[    4.405417]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[    4.405499]  ? __alloc_skb (net/core/skbuff.c:690)
[    4.405620]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[    4.405678]  ____sys_sendmsg (net/socket.c:727 net/socket.c:742 net/socket.c:2630)
[    4.405755]  ? copy_msghdr_from_user (net/socket.c:2570)
[    4.405830]  ___sys_sendmsg (net/socket.c:2686)
[    4.405922]  ? do_wp_page (./include/linux/mmu_notifier.h:468 mm/memory.c:3786 mm/memory.c:4140)
[    4.405998]  ? __handle_mm_fault (mm/memory.c:6193 mm/memory.c:6318)
[    4.406078]  __sys_sendmsg (net/socket.c:2716)
[    4.406149]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    4.406219]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    4.406298] RIP: 0033:0x7fbedcc991d7
[    4.406366] 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)
[    4.406603] RSP: 002b:00007ffc9c022c18 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[    4.406704] RAX: ffffffffffffffda RBX: 00007ffc9c023350 RCX: 00007fbedcc991d7
[    4.406796] RDX: 0000000000000000 RSI: 00007ffc9c022c80 RDI: 0000000000000005
[    4.406901] RBP: 0000000000000000 R08: 000000000000002c R09: 0000000000000008
[    4.406997] R10: 0000000000403668 R11: 0000000000000246 R12: 00007ffc9c023368
[    4.407098] R13: 00000000690de5bc R14: 0000000000499600 R15: 0000000000000000
| [    4.777912] ------------[ cut here ]------------
| [    4.778063] kernel BUG at net/core/net-sysfs.c:2246!
| [    4.778134] Oops: invalid opcode: 0000 [#1] SMP
| [    4.778283] Tainted: [W]=WARN
[    4.778312] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    4.778356] RIP: 0010:netdev_release (net/core/net-sysfs.c:2246 net/core/net-sysfs.c:2242)
[    4.778404] 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
[    4.778514] RSP: 0018:ffff9985c05c7bf0 EFLAGS: 00010297
[    4.778550] RAX: ffffffffaff5a5d0 RBX: 00000000ffffffff RCX: 0000000000000002
[    4.778601] RDX: 0000000000000006 RSI: ffffffffafd53ba4 RDI: ffff8d7282cf6530
[    4.778651] RBP: ffff8d7282cf6530 R08: 000000000000010c R09: 00000000000000a8
[    4.778702] R10: 00000000000000c0 R11: 00000000000000b0 R12: ffff8d7288a26500
[    4.778756] R13: ffffffffb02b1d20 R14: ffff8d72810507f0 R15: ffff8d7282cf6000
[    4.778809] FS:  00007f5672ee7000(0000) GS:ffff8d730dcb7000(0000) knlGS:0000000000000000
[    4.778863] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.778905] CR2: 00007f5672f47610 CR3: 000000000818e003 CR4: 0000000000772ef0
[    4.778957] PKRU: 55555554
[    4.778976] Call Trace:
[    4.779000]  <TASK>
[    4.779021]  device_release (drivers/base/core.c:2569)
[    4.779059]  kobject_put (lib/kobject.c:693 lib/kobject.c:720 ./include/linux/kref.h:65 lib/kobject.c:737)
[    4.779094]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    4.779139] nsim_destroy (drivers/net/netdevsim/netdevsim.h:396 drivers/net/netdevsim/netdev.c:1186) netdevsim
[    4.779192] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:441 drivers/net/netdevsim/dev.c:1474) netdevsim
[    4.779249] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:1483 drivers/net/netdevsim/dev.c:1707) netdevsim
[    4.779306] nsim_drv_remove (drivers/net/netdevsim/dev.c:1724) netdevsim
[    4.779412]  device_release_driver_internal (drivers/base/dd.c:1276 drivers/base/dd.c:1297)
[    4.779461]  bus_remove_device (./include/linux/kobject.h:193 (discriminator 3) drivers/base/base.h:73 (discriminator 3) drivers/base/bus.c:586 (discriminator 3))
[    4.779500]  device_del (drivers/base/core.c:3879)
[    4.779539]  device_unregister (drivers/base/core.c:3796 drivers/base/core.c:3920)
[    4.779586] del_device_store (drivers/net/netdevsim/bus.c:248) netdevsim
[    4.779644]  kernfs_fop_write_iter (fs/kernfs/file.c:88 fs/kernfs/file.c:356)
[    4.779702]  vfs_write (fs/read_write.c:594 fs/read_write.c:686)
[    4.779749]  ksys_write (fs/read_write.c:738)
[    4.779791]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    4.779840]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    4.779896] RIP: 0033:0x7f5672fe7257
[    4.779938] 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
[    4.780100] RSP: 002b:00007ffc8655d1b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[    4.780176] RAX: ffffffffffffffda RBX: 00007f56730e3780 RCX: 00007f5672fe7257
[    4.780256] RDX: 0000000000000004 RSI: 00005620207a6470 RDI: 0000000000000001
[    4.780331] RBP: 0000000000000004 R08: 0000000000000000 R09: 00007f5673099d20
[    4.780398] R10: 00007f5673099c20 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