======================================
| [   12.874073] ------------[ cut here ]------------
| [   12.874213] refcount_t: underflow; use-after-free.
| [   12.874294] WARNING: CPU: 2 PID: 1221 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [   12.874384] Modules linked in: ip_gre gre cls_u32 sch_htb
[   12.874537] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.874608] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[   12.874681] Code: ad e8 e8 54 ba ff 90 0f 0b 90 90 c3 80 3d 00 e6 2b 01 00 75 89 c6 05 f7 e5 2b 01 01 90 48 c7 c7 f8 48 55 ad e8 c5 54 ba ff 90 <0f> 0b 90 90 c3 80 3d db e5 2b 01 00 0f 85 62 ff ff ff c6 05 ce e5
All code
========
   0:	ad                   	lods   %ds:(%rsi),%eax
   1:	e8 e8 54 ba ff       	call   0xffffffffffba54ee
   6:	90                   	nop
   7:	0f 0b                	ud2
   9:	90                   	nop
   a:	90                   	nop
   b:	c3                   	ret
   c:	80 3d 00 e6 2b 01 00 	cmpb   $0x0,0x12be600(%rip)        # 0x12be613
  13:	75 89                	jne    0xffffffffffffff9e
  15:	c6 05 f7 e5 2b 01 01 	movb   $0x1,0x12be5f7(%rip)        # 0x12be613
  1c:	90                   	nop
  1d:	48 c7 c7 f8 48 55 ad 	mov    $0xffffffffad5548f8,%rdi
  24:	e8 c5 54 ba ff       	call   0xffffffffffba54ee
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	c3                   	ret
  2f:	80 3d db e5 2b 01 00 	cmpb   $0x0,0x12be5db(%rip)        # 0x12be611
  36:	0f 85 62 ff ff ff    	jne    0xffffffffffffff9e
  3c:	c6                   	.byte 0xc6
  3d:	05                   	.byte 0x5
  3e:	ce                   	(bad)
  3f:	e5                   	.byte 0xe5

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	c3                   	ret
   5:	80 3d db e5 2b 01 00 	cmpb   $0x0,0x12be5db(%rip)        # 0x12be5e7
   c:	0f 85 62 ff ff ff    	jne    0xffffffffffffff74
  12:	c6                   	.byte 0xc6
  13:	05                   	.byte 0x5
  14:	ce                   	(bad)
  15:	e5                   	.byte 0xe5
[   12.874820] RSP: 0018:ffffa23200767730 EFLAGS: 00010282
[   12.874881] RAX: 0000000000000000 RBX: ffffa23200767740 RCX: 00000000ffffdfff
[   12.874957] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   12.875043] RBP: ffffa23200767238 R08: ffffffffadd5ba28 R09: 00000000ffffdfff
[   12.875119] R10: ffffffffadc7ba40 R11: ffffffffadd2ba40 R12: dead000000000122
[   12.875201] R13: 00000000fffb9de8 R14: 0000000000000001 R15: ffff90f0c30a7000
[   12.875280] FS:  00007f37803e0800(0000) GS:ffff90f150891000(0000) knlGS:0000000000000000
[   12.875371] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   12.875440] CR2: 00000000004e64e8 CR3: 000000000916b003 CR4: 0000000000772ef0
[   12.875598] PKRU: 55555554
[   12.875654] Call Trace:
[   12.875710]  <TASK>
[   12.875764]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[   12.875836]  rtnl_dellink (net/core/rtnetlink.c:3580)
[   12.875912]  ? virtio_fs_enqueue_req (fs/fuse/virtio_fs.c:1473)
[   12.875995]  ? netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11653)
[   12.876068]  ? rtnl_bridge_getlink (net/core/rtnetlink.c:3536)
[   12.876147]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)
[   12.876216]  ? get_page_from_freelist (mm/page_alloc.c:1226 mm/page_alloc.c:1848 mm/page_alloc.c:1858 mm/page_alloc.c:3884)
[   12.876296]  ? rtnl_calcit.isra.0 (net/core/rtnetlink.c:6861)
[   12.876378]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[   12.876449]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[   12.876517]  ? __alloc_skb (net/core/skbuff.c:690)
[   12.876586]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[   12.876654]  ____sys_sendmsg (net/socket.c:727 net/socket.c:742 net/socket.c:2630)
[   12.876726]  ? copy_msghdr_from_user (net/socket.c:2570)
[   12.876807]  ___sys_sendmsg (net/socket.c:2686)
[   12.876874]  ? do_wp_page (./include/linux/mmu_notifier.h:468 mm/memory.c:3786 mm/memory.c:4140)
[   12.876942]  ? ___pte_offset_map (./include/linux/pgtable.h:347 ./include/linux/pgtable.h:635 mm/pgtable-generic.c:288)
[   12.877011]  ? nfulnl_rcv_nl_event (net/netfilter/nfnetlink_log.c:836)
[   12.877103]  ? fsnotify_grab_connector (fs/notify/mark.c:709)
[   12.877184]  ? fsnotify_destroy_marks (fs/notify/mark.c:937)
[   12.877278]  __sys_sendmsg (net/socket.c:2716)
[   12.877340]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[   12.877411]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   12.877488] RIP: 0033:0x7f37805ae1d7
[   12.877551] 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)
[   12.877779] RSP: 002b:00007fff6cb356e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   12.877883] RAX: ffffffffffffffda RBX: 00007fff6cb35e10 RCX: 00007f37805ae1d7
[   12.877984] RDX: 0000000000000000 RSI: 00007fff6cb35750 RDI: 0000000000000005
[   12.878089] RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000078
[   12.878195] R10: 00007f37804aaf60 R11: 0000000000000246 R12: 0000000000000001
[   12.878300] R13: 00000000690de770 R14: 0000000000499600 R15: 0000000000000000
| [   28.737085] ------------[ cut here ]------------
| [   28.737208] kernel BUG at net/core/net-sysfs.c:2246!
| [   28.737263] Oops: invalid opcode: 0000 [#1] SMP
| [   28.737454] Tainted: [W]=WARN
[   28.737495] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   28.737564] RIP: 0010:netdev_release (net/core/net-sysfs.c:2246 net/core/net-sysfs.c:2242)
[   28.737628] Code: fa 0f 1f 44 00 00 80 7f d8 04 75 1d 55 48 8d af a8 fa ff ff 48 8b bf e0 fb ff ff e8 ed d7 a4 ff 48 89 ef 5d e9 a4 de a4 ff 90 <0f> 0b 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 f5 48 8d 97 c8 fb ff
All code
========
   0:	fa                   	cli
   1:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   6:	80 7f d8 04          	cmpb   $0x4,-0x28(%rdi)
   a:	75 1d                	jne    0x29
   c:	55                   	push   %rbp
   d:	48 8d af a8 fa ff ff 	lea    -0x558(%rdi),%rbp
  14:	48 8b bf e0 fb ff ff 	mov    -0x420(%rdi),%rdi
  1b:	e8 ed d7 a4 ff       	call   0xffffffffffa4d80d
  20:	48 89 ef             	mov    %rbp,%rdi
  23:	5d                   	pop    %rbp
  24:	e9 a4 de a4 ff       	jmp    0xffffffffffa4decd
  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:	c8                   	.byte 0xc8
  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:	c8                   	.byte 0xc8
  14:	fb                   	sti
  15:	ff                   	.byte 0xff
[   28.737823] RSP: 0018:ffffa232005f7bf0 EFLAGS: 00010297
[   28.737890] RAX: ffffffffacf51ca0 RBX: 00000000ffffffff RCX: 0000000000000003
[   28.737972] RDX: 0000000000000007 RSI: ffffffffacd58ea4 RDI: ffff90f0c2dba558
[   28.738052] RBP: ffff90f0c2dba558 R08: 0000000000000010 R09: 0000000000000298
[   28.738130] R10: 0000000000000400 R11: 00000000000002a0 R12: ffff90f0c96cc300
[   28.738212] R13: ffffffffad2b2ea0 R14: ffff90f0c1b80190 R15: ffff90f0c2dba000
[   28.738293] FS:  00007f1d9c1dc000(0000) GS:ffff90f150911000(0000) knlGS:0000000000000000
[   28.738379] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   28.738450] CR2: 000055739a83b3b0 CR3: 0000000005c24006 CR4: 0000000000772ef0
[   28.738530] PKRU: 55555554
[   28.738562] Call Trace:
[   28.738590]  <TASK>
[   28.738622]  device_release (drivers/base/core.c:2569)
[   28.738670]  kobject_put (lib/kobject.c:693 lib/kobject.c:720 ./include/linux/kref.h:65 lib/kobject.c:737)
[   28.738716]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[   28.738766] nsim_destroy (drivers/net/netdevsim/netdevsim.h:396 drivers/net/netdevsim/netdev.c:1186) netdevsim
[   28.738832] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:441 drivers/net/netdevsim/dev.c:1474) netdevsim
[   28.738890] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:1483 drivers/net/netdevsim/dev.c:1707) netdevsim
[   28.738949] nsim_drv_remove (drivers/net/netdevsim/dev.c:1724) netdevsim
[   28.739007]  device_release_driver_internal (drivers/base/dd.c:1276 drivers/base/dd.c:1297)
[   28.739066]  bus_remove_device (./include/linux/kobject.h:193 (discriminator 3) drivers/base/base.h:73 (discriminator 3) drivers/base/bus.c:586 (discriminator 3))
[   28.739112]  device_del (drivers/base/core.c:3879)
[   28.739159]  device_unregister (drivers/base/core.c:3796 drivers/base/core.c:3920)
[   28.739205] del_device_store (drivers/net/netdevsim/bus.c:248) netdevsim
[   28.739266]  kernfs_fop_write_iter (fs/kernfs/file.c:88 fs/kernfs/file.c:356)
[   28.739326]  vfs_write (fs/read_write.c:594 fs/read_write.c:686)
[   28.739373]  ksys_write (fs/read_write.c:738)
[   28.739420]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[   28.739468]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   28.739527] RIP: 0033:0x7f1d9c2dc257
[   28.739574] 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
[   28.739759] RSP: 002b:00007ffce82d1a58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   28.739843] RAX: ffffffffffffffda RBX: 00007f1d9c3d8780 RCX: 00007f1d9c2dc257
[   28.739948] RDX: 0000000000000002 RSI: 000055739a83b3b0 RDI: 0000000000000001
[   28.740025] RBP: 0000000000000002 R08: 0000000000000000 R09: 00007f1d9c38ed20
[   28.740102] R10: 00007f1d9c38ec20 R11: 0000000000000246 R12: 0000000000000002


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