======================================
| [   82.579804] ------------[ cut here ]------------
| [   82.580238] refcount_t: underflow; use-after-free.
| [   82.580879] WARNING: CPU: 3 PID: 69 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
| [   82.582002] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   82.584087] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   82.585047] Workqueue: netns cleanup_net
[   82.585310] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
[ 82.585741] Code: 0b 90 90 c3 cc cc cc cc 80 3d 69 d4 67 01 00 0f 85 75 ff ff ff c6 05 5c d4 67 01 01 90 48 c7 c7 b8 37 53 b7 e8 a1 26 b4 ff 90 <0f> 0b 90 90 c3 cc cc cc cc 80 3d 3c d4 67 01 00 0f 85 4a ff ff ff
All code
========
   0:	0b 90 90 c3 cc cc    	or     -0x33333c70(%rax),%edx
   6:	cc                   	int3
   7:	cc                   	int3
   8:	80 3d 69 d4 67 01 00 	cmpb   $0x0,0x167d469(%rip)        # 0x167d478
   f:	0f 85 75 ff ff ff    	jne    0xffffffffffffff8a
  15:	c6 05 5c d4 67 01 01 	movb   $0x1,0x167d45c(%rip)        # 0x167d478
  1c:	90                   	nop
  1d:	48 c7 c7 b8 37 53 b7 	mov    $0xffffffffb75337b8,%rdi
  24:	e8 a1 26 b4 ff       	call   0xffffffffffb426ca
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	c3                   	ret
  2f:	cc                   	int3
  30:	cc                   	int3
  31:	cc                   	int3
  32:	cc                   	int3
  33:	80 3d 3c d4 67 01 00 	cmpb   $0x0,0x167d43c(%rip)        # 0x167d476
  3a:	0f 85 4a ff ff ff    	jne    0xffffffffffffff8a

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	c3                   	ret
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	80 3d 3c d4 67 01 00 	cmpb   $0x0,0x167d43c(%rip)        # 0x167d44c
  10:	0f 85 4a ff ff ff    	jne    0xffffffffffffff60
[   82.586736] RSP: 0018:ffff9fe74026bd78 EFLAGS: 00010286
[   82.587021] RAX: 0000000000000000 RBX: ffff922cc1934000 RCX: 00000000ffffdfff
[   82.587650] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   82.588168] RBP: ffff922cc1934610 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   82.588708] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc1934000
[   82.589366] R13: ffff9fe74026be08 R14: ffff922cc1934b80 R15: ffff922cc41b0050
[   82.590100] FS:  0000000000000000(0000) GS:ffff922cfed80000(0000) knlGS:0000000000000000
[   82.590922] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   82.591472] CR2: 00007ffd152a0658 CR3: 0000000017e60003 CR4: 0000000000770ef0
[   82.592229] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   82.592918] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   82.593555] PKRU: 55555554
[   82.593784] Call Trace:
[   82.594011]  <TASK>
[   82.594254] ? __warn (kernel/panic.c:677) 
[   82.594551] ? refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
[   82.594939] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   82.595259] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   82.595574] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   82.595897] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   82.596251] ? refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
[   82.596598] ? refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
[   82.596999] br_sysfs_delbr (net/bridge/br_sysfs_br.c:1086) 
[   82.597292] br_dev_delete (net/bridge/br_if.c:396) 
[   82.597614] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   82.597972] cleanup_net (net/core/net_namespace.c:630) 
[   82.598284] ? process_one_work (kernel/workqueue.c:2606) 
[   82.598661] process_one_work (kernel/workqueue.c:2633) 
[   82.598969] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   82.599318] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   82.599669] kthread (kernel/kthread.c:388) 
[   82.599932] ? __pfx_kthread (kernel/kthread.c:341) 
[   82.600183] ret_from_fork (arch/x86/kernel/process.c:147) 
[   82.600388] ? __pfx_kthread (kernel/kthread.c:341) 
[   82.600619] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   82.603479] ------------[ cut here ]------------
| [   82.603815] sysfs group 'bridge' not found for kobject 'br0'
| [   82.604381] WARNING: CPU: 3 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   82.604937] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   82.607300] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   82.608297] Workqueue: netns cleanup_net
[   82.608746] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 82.609269] Code: 48 89 ef 5d 41 5c e9 7a ad ff ff 48 89 ef e8 12 9b ff ff eb d1 90 49 8b 14 24 48 8b 33 48 c7 c7 a0 cd 52 b7 e8 ac 67 c5 ff 90 <0f> 0b 90 90 5b 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
All code
========
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	41 5c                	pop    %r12
   6:	e9 7a ad ff ff       	jmp    0xffffffffffffad85
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 12 9b ff ff       	call   0xffffffffffff9b25
  13:	eb d1                	jmp    0xffffffffffffffe6
  15:	90                   	nop
  16:	49 8b 14 24          	mov    (%r12),%rdx
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 cd 52 b7 	mov    $0xffffffffb752cda0,%rdi
  24:	e8 ac 67 c5 ff       	call   0xffffffffffc567d5
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	41 5c                	pop    %r12
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	5b                   	pop    %rbx
   5:	5d                   	pop    %rbp
   6:	41 5c                	pop    %r12
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	66                   	data16
   e:	66                   	data16
   f:	2e                   	cs
  10:	0f                   	.byte 0xf
  11:	1f                   	(bad)
  12:	84 00                	test   %al,(%rax)
	...
[   82.610963] RSP: 0018:ffff9fe74026bd70 EFLAGS: 00010286
[   82.611477] RAX: 0000000000000000 RBX: ffffffffb71472c0 RCX: 00000000ffffdfff
[   82.612182] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   82.612942] RBP: 0000000000000000 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   82.613770] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc1934610
[   82.614714] R13: ffff9fe74026be08 R14: ffff922cc1934b80 R15: ffff922cc41b0050
[   82.615600] FS:  0000000000000000(0000) GS:ffff922cfed80000(0000) knlGS:0000000000000000
[   82.616201] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   82.616674] CR2: 00007ffd152a0658 CR3: 0000000017e60003 CR4: 0000000000770ef0
[   82.617154] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   82.617715] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   82.618476] PKRU: 55555554
[   82.618670] Call Trace:
[   82.618927]  <TASK>
[   82.619118] ? __warn (kernel/panic.c:677) 
[   82.619577] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   82.620061] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   82.620620] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   82.621070] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   82.621453] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   82.621873] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   82.622306] br_dev_delete (net/bridge/br_if.c:396) 
[   82.622647] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   82.623099] cleanup_net (net/core/net_namespace.c:630) 
[   82.623459] ? process_one_work (kernel/workqueue.c:2606) 
[   82.623863] process_one_work (kernel/workqueue.c:2633) 
[   82.624276] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   82.624640] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   82.625068] kthread (kernel/kthread.c:388) 
[   82.625366] ? __pfx_kthread (kernel/kthread.c:341) 
[   82.625760] ret_from_fork (arch/x86/kernel/process.c:147) 
[   82.626141] ? __pfx_kthread (kernel/kthread.c:341) 
[   82.626529] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   82.713757] ------------[ cut here ]------------
| [   82.714050] sysfs group 'bridge' not found for kobject 'br0'
| [   82.714383] WARNING: CPU: 1 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   82.715010] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   82.716782] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   82.717807] Workqueue: netns cleanup_net
[   82.718166] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 82.718626] Code: 48 89 ef 5d 41 5c e9 7a ad ff ff 48 89 ef e8 12 9b ff ff eb d1 90 49 8b 14 24 48 8b 33 48 c7 c7 a0 cd 52 b7 e8 ac 67 c5 ff 90 <0f> 0b 90 90 5b 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
All code
========
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	41 5c                	pop    %r12
   6:	e9 7a ad ff ff       	jmp    0xffffffffffffad85
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 12 9b ff ff       	call   0xffffffffffff9b25
  13:	eb d1                	jmp    0xffffffffffffffe6
  15:	90                   	nop
  16:	49 8b 14 24          	mov    (%r12),%rdx
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 cd 52 b7 	mov    $0xffffffffb752cda0,%rdi
  24:	e8 ac 67 c5 ff       	call   0xffffffffffc567d5
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	41 5c                	pop    %r12
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	5b                   	pop    %rbx
   5:	5d                   	pop    %rbp
   6:	41 5c                	pop    %r12
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	66                   	data16
   e:	66                   	data16
   f:	2e                   	cs
  10:	0f                   	.byte 0xf
  11:	1f                   	(bad)
  12:	84 00                	test   %al,(%rax)
	...
[   82.720397] RSP: 0018:ffff9fe74026bd70 EFLAGS: 00010286
[   82.720892] RAX: 0000000000000000 RBX: ffffffffb71472c0 RCX: 00000000ffffdfff
[   82.721604] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   82.722275] RBP: 0000000000000000 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   82.722959] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc43f8610
[   82.723516] R13: ffff9fe74026be08 R14: ffff922cc43f8b80 R15: ffff922cc41b0050
[   82.724113] FS:  0000000000000000(0000) GS:ffff922cfec80000(0000) knlGS:0000000000000000
[   82.724858] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   82.725346] CR2: 000055ea7b0fcd68 CR3: 0000000017e60004 CR4: 0000000000770ef0
[   82.725966] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   82.726619] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   82.727145] PKRU: 55555554
[   82.727292] Call Trace:
[   82.727428]  <TASK>
[   82.727590] ? __warn (kernel/panic.c:677) 
[   82.727816] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   82.728075] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   82.728473] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   82.728698] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   82.728911] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   82.729160] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   82.729399] br_dev_delete (net/bridge/br_if.c:396) 
[   82.729668] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   82.730055] cleanup_net (net/core/net_namespace.c:630) 
[   82.730396] ? process_one_work (kernel/workqueue.c:2606) 
[   82.730755] process_one_work (kernel/workqueue.c:2633) 
[   82.731018] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   82.731356] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   82.731704] kthread (kernel/kthread.c:388) 
[   82.731970] ? __pfx_kthread (kernel/kthread.c:341) 
[   82.732173] ret_from_fork (arch/x86/kernel/process.c:147) 
[   82.732369] ? __pfx_kthread (kernel/kthread.c:341) 
[   82.732654] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   86.221917] ------------[ cut here ]------------
| [   86.222180] sysfs group 'bridge' not found for kobject 'br0'
| [   86.222506] WARNING: CPU: 3 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   86.223126] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   86.224534] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   86.225467] Workqueue: netns cleanup_net
[   86.225813] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 86.226228] Code: 48 89 ef 5d 41 5c e9 7a ad ff ff 48 89 ef e8 12 9b ff ff eb d1 90 49 8b 14 24 48 8b 33 48 c7 c7 a0 cd 52 b7 e8 ac 67 c5 ff 90 <0f> 0b 90 90 5b 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
All code
========
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	41 5c                	pop    %r12
   6:	e9 7a ad ff ff       	jmp    0xffffffffffffad85
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 12 9b ff ff       	call   0xffffffffffff9b25
  13:	eb d1                	jmp    0xffffffffffffffe6
  15:	90                   	nop
  16:	49 8b 14 24          	mov    (%r12),%rdx
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 cd 52 b7 	mov    $0xffffffffb752cda0,%rdi
  24:	e8 ac 67 c5 ff       	call   0xffffffffffc567d5
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	41 5c                	pop    %r12
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	5b                   	pop    %rbx
   5:	5d                   	pop    %rbp
   6:	41 5c                	pop    %r12
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	66                   	data16
   e:	66                   	data16
   f:	2e                   	cs
  10:	0f                   	.byte 0xf
  11:	1f                   	(bad)
  12:	84 00                	test   %al,(%rax)
	...
[   86.227777] RSP: 0018:ffff9fe74026bd70 EFLAGS: 00010286
[   86.228229] RAX: 0000000000000000 RBX: ffffffffb71472c0 RCX: 00000000ffffdfff
[   86.228780] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   86.229384] RBP: 0000000000000000 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   86.230007] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc43fc610
[   86.230626] R13: ffff9fe74026be08 R14: ffff922cc43fcb80 R15: ffff922cc4eb1750
[   86.231240] FS:  0000000000000000(0000) GS:ffff922cfed80000(0000) knlGS:0000000000000000
[   86.231915] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   86.232377] CR2: 000055ea7a6965a0 CR3: 0000000017e60003 CR4: 0000000000770ef0
[   86.232991] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   86.233578] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   86.234147] PKRU: 55555554
[   86.234388] Call Trace:
[   86.234561]  <TASK>
[   86.234757] ? __warn (kernel/panic.c:677) 
[   86.235051] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   86.235370] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   86.235699] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   86.235889] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   86.236094] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   86.236345] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   86.236662] br_dev_delete (net/bridge/br_if.c:396) 
[   86.236909] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   86.237168] cleanup_net (net/core/net_namespace.c:630) 
[   86.237489] ? process_one_work (kernel/workqueue.c:2606) 
[   86.237722] process_one_work (kernel/workqueue.c:2633) 
[   86.237939] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   86.238141] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   86.238444] kthread (kernel/kthread.c:388) 
[   86.238693] ? __pfx_kthread (kernel/kthread.c:341) 
[   86.239024] ret_from_fork (arch/x86/kernel/process.c:147) 
[   86.239234] ? __pfx_kthread (kernel/kthread.c:341) 
[   86.239437] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   86.350706] ------------[ cut here ]------------
| [   86.350977] sysfs group 'bridge' not found for kobject 'br0'
| [   86.351351] WARNING: CPU: 0 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   86.351881] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   86.353158] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   86.353780] Workqueue: netns cleanup_net
[   86.354030] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 86.354344] Code: 48 89 ef 5d 41 5c e9 7a ad ff ff 48 89 ef e8 12 9b ff ff eb d1 90 49 8b 14 24 48 8b 33 48 c7 c7 a0 cd 52 b7 e8 ac 67 c5 ff 90 <0f> 0b 90 90 5b 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
All code
========
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	41 5c                	pop    %r12
   6:	e9 7a ad ff ff       	jmp    0xffffffffffffad85
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 12 9b ff ff       	call   0xffffffffffff9b25
  13:	eb d1                	jmp    0xffffffffffffffe6
  15:	90                   	nop
  16:	49 8b 14 24          	mov    (%r12),%rdx
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 cd 52 b7 	mov    $0xffffffffb752cda0,%rdi
  24:	e8 ac 67 c5 ff       	call   0xffffffffffc567d5
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	41 5c                	pop    %r12
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	5b                   	pop    %rbx
   5:	5d                   	pop    %rbp
   6:	41 5c                	pop    %r12
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	66                   	data16
   e:	66                   	data16
   f:	2e                   	cs
  10:	0f                   	.byte 0xf
  11:	1f                   	(bad)
  12:	84 00                	test   %al,(%rax)
	...
[   86.355347] RSP: 0018:ffff9fe74026bd70 EFLAGS: 00010286
[   86.355647] RAX: 0000000000000000 RBX: ffffffffb71472c0 RCX: 00000000ffffdfff
[   86.356062] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   86.356500] RBP: 0000000000000000 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   86.356893] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc20da610
[   86.357285] R13: ffff9fe74026be08 R14: ffff922cc20dab80 R15: ffffffffb8e78f90
[   86.357693] FS:  0000000000000000(0000) GS:ffff922cfec00000(0000) knlGS:0000000000000000
[   86.358186] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   86.358567] CR2: 00007fce51cb2270 CR3: 0000000017e60002 CR4: 0000000000770ef0
[   86.358979] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   86.359419] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   86.359838] PKRU: 55555554
[   86.360058] Call Trace:
[   86.360226]  <TASK>
[   86.360388] ? __warn (kernel/panic.c:677) 
[   86.360628] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   86.360907] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   86.361163] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   86.361381] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   86.361624] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   86.361908] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   86.362173] br_dev_delete (net/bridge/br_if.c:396) 
[   86.362403] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   86.362680] cleanup_net (net/core/net_namespace.c:630) 
[   86.362924] ? process_one_work (kernel/workqueue.c:2606) 
[   86.363174] process_one_work (kernel/workqueue.c:2633) 
[   86.363421] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   86.363669] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   86.363974] kthread (kernel/kthread.c:388) 
[   86.364178] ? __pfx_kthread (kernel/kthread.c:341) 
[   86.364412] ret_from_fork (arch/x86/kernel/process.c:147) 
[   86.364688] ? __pfx_kthread (kernel/kthread.c:341) 
[   86.364946] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   95.873706] ------------[ cut here ]------------
| [   95.874171] sysfs group 'bridge' not found for kobject 'br0'
| [   95.874635] WARNING: CPU: 3 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   95.875081] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   95.876321] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   95.876918] Workqueue: netns cleanup_net
[   95.877135] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 95.877388] Code: 48 89 ef 5d 41 5c e9 7a ad ff ff 48 89 ef e8 12 9b ff ff eb d1 90 49 8b 14 24 48 8b 33 48 c7 c7 a0 cd 52 b7 e8 ac 67 c5 ff 90 <0f> 0b 90 90 5b 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
All code
========
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	41 5c                	pop    %r12
   6:	e9 7a ad ff ff       	jmp    0xffffffffffffad85
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 12 9b ff ff       	call   0xffffffffffff9b25
  13:	eb d1                	jmp    0xffffffffffffffe6
  15:	90                   	nop
  16:	49 8b 14 24          	mov    (%r12),%rdx
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 cd 52 b7 	mov    $0xffffffffb752cda0,%rdi
  24:	e8 ac 67 c5 ff       	call   0xffffffffffc567d5
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	41 5c                	pop    %r12
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	5b                   	pop    %rbx
   5:	5d                   	pop    %rbp
   6:	41 5c                	pop    %r12
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	66                   	data16
   e:	66                   	data16
   f:	2e                   	cs
  10:	0f                   	.byte 0xf
  11:	1f                   	(bad)
  12:	84 00                	test   %al,(%rax)
	...
[   95.878352] RSP: 0018:ffff9fe74026bd70 EFLAGS: 00010286
[   95.878642] RAX: 0000000000000000 RBX: ffffffffb71472c0 RCX: 00000000ffffdfff
[   95.879016] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   95.879381] RBP: 0000000000000000 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   95.879764] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc43fa610
[   95.880132] R13: ffff9fe74026be08 R14: ffff922cc43fab80 R15: ffff922cc4eb2e50
[   95.880506] FS:  0000000000000000(0000) GS:ffff922cfed80000(0000) knlGS:0000000000000000
[   95.880925] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   95.881223] CR2: 00007f90a508a000 CR3: 0000000017e60003 CR4: 0000000000770ef0
[   95.881598] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   95.881966] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   95.882331] PKRU: 55555554
[   95.882480] Call Trace:
[   95.882641]  <TASK>
[   95.882771] ? __warn (kernel/panic.c:677) 
[   95.882948] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   95.883169] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   95.883367] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   95.883562] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   95.883773] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   95.884000] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   95.884222] br_dev_delete (net/bridge/br_if.c:396) 
[   95.884418] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   95.884658] cleanup_net (net/core/net_namespace.c:630) 
[   95.884854] ? process_one_work (kernel/workqueue.c:2606) 
[   95.885078] process_one_work (kernel/workqueue.c:2633) 
[   95.885293] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   95.885502] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   95.885730] kthread (kernel/kthread.c:388) 
[   95.885902] ? __pfx_kthread (kernel/kthread.c:341) 
[   95.886103] ret_from_fork (arch/x86/kernel/process.c:147) 
[   95.886298] ? __pfx_kthread (kernel/kthread.c:341) 
[   95.886506] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   96.013738] ------------[ cut here ]------------
| [   96.014009] sysfs group 'bridge' not found for kobject 'br0'
| [   96.014341] WARNING: CPU: 0 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   96.014787] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   96.016058] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   96.016670] Workqueue: netns cleanup_net
[   96.016900] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 96.017199] Code: 48 89 ef 5d 41 5c e9 7a ad ff ff 48 89 ef e8 12 9b ff ff eb d1 90 49 8b 14 24 48 8b 33 48 c7 c7 a0 cd 52 b7 e8 ac 67 c5 ff 90 <0f> 0b 90 90 5b 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
All code
========
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	41 5c                	pop    %r12
   6:	e9 7a ad ff ff       	jmp    0xffffffffffffad85
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 12 9b ff ff       	call   0xffffffffffff9b25
  13:	eb d1                	jmp    0xffffffffffffffe6
  15:	90                   	nop
  16:	49 8b 14 24          	mov    (%r12),%rdx
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 cd 52 b7 	mov    $0xffffffffb752cda0,%rdi
  24:	e8 ac 67 c5 ff       	call   0xffffffffffc567d5
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	41 5c                	pop    %r12
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	5b                   	pop    %rbx
   5:	5d                   	pop    %rbp
   6:	41 5c                	pop    %r12
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	66                   	data16
   e:	66                   	data16
   f:	2e                   	cs
  10:	0f                   	.byte 0xf
  11:	1f                   	(bad)
  12:	84 00                	test   %al,(%rax)
	...
[   96.018172] RSP: 0018:ffff9fe74026bd70 EFLAGS: 00010286
[   96.018504] RAX: 0000000000000000 RBX: ffffffffb71472c0 RCX: 00000000ffffdfff
[   96.018899] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   96.019280] RBP: 0000000000000000 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   96.019683] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc5b96610
[   96.020086] R13: ffff9fe74026be08 R14: ffff922cc5b96b80 R15: ffffffffb8e78f90
[   96.020518] FS:  0000000000000000(0000) GS:ffff922cfec00000(0000) knlGS:0000000000000000
[   96.020955] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   96.021273] CR2: 00007fa13e1a9000 CR3: 0000000017e60002 CR4: 0000000000770ef0
[   96.021684] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   96.022053] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   96.022444] PKRU: 55555554
[   96.022598] Call Trace:
[   96.022761]  <TASK>
[   96.022916] ? __warn (kernel/panic.c:677) 
[   96.023118] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   96.023365] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   96.023574] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   96.023764] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   96.023972] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   96.024200] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   96.024425] br_dev_delete (net/bridge/br_if.c:396) 
[   96.024628] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   96.024862] cleanup_net (net/core/net_namespace.c:630) 
[   96.025059] ? process_one_work (kernel/workqueue.c:2606) 
[   96.025284] process_one_work (kernel/workqueue.c:2633) 
[   96.025507] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   96.025707] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   96.025935] kthread (kernel/kthread.c:388) 
[   96.026109] ? __pfx_kthread (kernel/kthread.c:341) 
[   96.026310] ret_from_fork (arch/x86/kernel/process.c:147) 
[   96.026511] ? __pfx_kthread (kernel/kthread.c:341) 
[   96.026711] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   99.407838] ------------[ cut here ]------------
| [   99.408720] sysfs group 'bridge' not found for kobject 'br0'
| [   99.409705] WARNING: CPU: 1 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   99.411094] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   99.415087] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   99.416761] Workqueue: netns cleanup_net
[   99.417363] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 99.417764] Code: 48 89 ef 5d 41 5c e9 7a ad ff ff 48 89 ef e8 12 9b ff ff eb d1 90 49 8b 14 24 48 8b 33 48 c7 c7 a0 cd 52 b7 e8 ac 67 c5 ff 90 <0f> 0b 90 90 5b 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
All code
========
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	41 5c                	pop    %r12
   6:	e9 7a ad ff ff       	jmp    0xffffffffffffad85
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 12 9b ff ff       	call   0xffffffffffff9b25
  13:	eb d1                	jmp    0xffffffffffffffe6
  15:	90                   	nop
  16:	49 8b 14 24          	mov    (%r12),%rdx
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 cd 52 b7 	mov    $0xffffffffb752cda0,%rdi
  24:	e8 ac 67 c5 ff       	call   0xffffffffffc567d5
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	41 5c                	pop    %r12
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	5b                   	pop    %rbx
   5:	5d                   	pop    %rbp
   6:	41 5c                	pop    %r12
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	66                   	data16
   e:	66                   	data16
   f:	2e                   	cs
  10:	0f                   	.byte 0xf
  11:	1f                   	(bad)
  12:	84 00                	test   %al,(%rax)
	...
[   99.419549] RSP: 0018:ffff9fe74026bd70 EFLAGS: 00010286
[   99.420077] RAX: 0000000000000000 RBX: ffffffffb71472c0 RCX: 00000000ffffdfff
[   99.420860] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   99.421908] RBP: 0000000000000000 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   99.423080] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc5b96610
[   99.424206] R13: ffff9fe74026be08 R14: ffff922cc5b96b80 R15: ffff922cc5a8c550
[   99.425382] FS:  0000000000000000(0000) GS:ffff922cfec80000(0000) knlGS:0000000000000000
[   99.426711] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   99.427645] CR2: 00007f2e24f39000 CR3: 0000000001ef0006 CR4: 0000000000770ef0
[   99.428687] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   99.429714] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   99.430651] PKRU: 55555554
[   99.431070] Call Trace:
[   99.431415]  <TASK>
[   99.431708] ? __warn (kernel/panic.c:677) 
[   99.431972] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   99.432363] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   99.432681] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   99.432970] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   99.433282] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   99.433634] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   99.433974] br_dev_delete (net/bridge/br_if.c:396) 
[   99.434269] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   99.434637] cleanup_net (net/core/net_namespace.c:630) 
[   99.434940] ? process_one_work (kernel/workqueue.c:2606) 
[   99.435277] process_one_work (kernel/workqueue.c:2633) 
[   99.435610] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   99.435916] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   99.436259] kthread (kernel/kthread.c:388) 
[   99.436527] ? __pfx_kthread (kernel/kthread.c:341) 
[   99.436833] ret_from_fork (arch/x86/kernel/process.c:147) 
[   99.437127] ? __pfx_kthread (kernel/kthread.c:341) 
[   99.437429] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| xx__-> [   99.521971] ------------[ cut here ]------------
| [   99.522222] sysfs group 'bridge' not found for kobject 'br0'
| [   99.522553] WARNING: CPU: 1 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   99.522971] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel nft_chain_nat xt_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c
[   99.524239] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   99.524866] Workqueue: netns cleanup_net
[   99.525088] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 99.525351] Code: 48 89 ef 5d 41 5c e9 7a ad ff ff 48 89 ef e8 12 9b ff ff eb d1 90 49 8b 14 24 48 8b 33 48 c7 c7 a0 cd 52 b7 e8 ac 67 c5 ff 90 <0f> 0b 90 90 5b 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
All code
========
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	41 5c                	pop    %r12
   6:	e9 7a ad ff ff       	jmp    0xffffffffffffad85
   b:	48 89 ef             	mov    %rbp,%rdi
   e:	e8 12 9b ff ff       	call   0xffffffffffff9b25
  13:	eb d1                	jmp    0xffffffffffffffe6
  15:	90                   	nop
  16:	49 8b 14 24          	mov    (%r12),%rdx
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 cd 52 b7 	mov    $0xffffffffb752cda0,%rdi
  24:	e8 ac 67 c5 ff       	call   0xffffffffffc567d5
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	41 5c                	pop    %r12
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	5b                   	pop    %rbx
   5:	5d                   	pop    %rbp
   6:	41 5c                	pop    %r12
   8:	c3                   	ret
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	66                   	data16
   e:	66                   	data16
   f:	2e                   	cs
  10:	0f                   	.byte 0xf
  11:	1f                   	(bad)
  12:	84 00                	test   %al,(%rax)
	...
[   99.526401] RSP: 0018:ffff9fe74026bd70 EFLAGS: 00010286
[   99.526681] RAX: 0000000000000000 RBX: ffffffffb71472c0 RCX: 00000000ffffdfff
[   99.527071] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[   99.527468] RBP: 0000000000000000 R08: ffffffffb7978508 R09: 00000000ffffdfff
[   99.527862] R10: ffffffffb7898520 R11: ffffffffb7948520 R12: ffff922cc20de610
[   99.528260] R13: ffff9fe74026be08 R14: ffff922cc20deb80 R15: ffffffffb8e78f90
[   99.528667] FS:  0000000000000000(0000) GS:ffff922cfec80000(0000) knlGS:0000000000000000
[   99.529085] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   99.529402] CR2: 00007f0f7c6950e0 CR3: 0000000017e60005 CR4: 0000000000770ef0
[   99.529800] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   99.530197] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   99.530594] PKRU: 55555554
[   99.530758] Call Trace:
[   99.530912]  <TASK>
[   99.531032] ? __warn (kernel/panic.c:677) 
[   99.531208] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   99.531434] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[   99.531643] ? handle_bug (arch/x86/kernel/traps.c:238) 
[   99.531834] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[   99.532040] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[   99.532269] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[   99.532500] br_dev_delete (net/bridge/br_if.c:396) 
[   99.532696] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[   99.532949] cleanup_net (net/core/net_namespace.c:630) 
[   99.533153] ? process_one_work (kernel/workqueue.c:2606) 
[   99.533389] process_one_work (kernel/workqueue.c:2633) 
[   99.533631] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[   99.533834] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[   99.534063] kthread (kernel/kthread.c:388) 
[   99.534256] ? __pfx_kthread (kernel/kthread.c:341) 
[   99.534463] ret_from_fork (arch/x86/kernel/process.c:147) 
[   99.534679] ? __pfx_kthread (kernel/kthread.c:341) 


Finger prints:
refcount_warn_saturate:br_sysfs_delbr:br_dev_delete:br_net_exit_batch_rtnl
sysfs_remove_group:br_dev_delete:br_net_exit_batch_rtnl:cleanup_net
sysfs_remove_group:br_dev_delete:br_net_exit_batch_rtnl:cleanup_net
sysfs_remove_group:br_dev_delete:br_net_exit_batch_rtnl:cleanup_net
sysfs_remove_group:br_dev_delete:br_net_exit_batch_rtnl:cleanup_net
sysfs_remove_group:br_dev_delete:br_net_exit_batch_rtnl:cleanup_net
sysfs_remove_group:br_dev_delete:br_net_exit_batch_rtnl:cleanup_net
sysfs_remove_group:br_dev_delete:br_net_exit_batch_rtnl:cleanup_net
sysfs_remove_group:br_dev_delete:br_net_exit_batch_rtnl:cleanup_net