======================================
| [   41.480692][   T69] ==================================================================
| [ 41.481131][ T69] BUG: KASAN: slab-use-after-free in kobject_put (lib/kobject.c:729) 
| [   41.481523][   T69] Read of size 1 at addr ffff8880031486bc by task kworker/u8:1/69
| [   41.481937][   T69]
[   41.482524][   T69] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   41.483157][   T69] Workqueue: netns cleanup_net
[   41.483413][   T69] Call Trace:
[   41.483596][   T69]  <TASK>
[ 41.483752][ T69] dump_stack_lvl (lib/dump_stack.c:107) 
[ 41.483994][ T69] print_address_description.constprop.0 (mm/kasan/report.c:378) 
[ 41.484381][ T69] ? kobject_put (lib/kobject.c:729) 
[ 41.484639][ T69] print_report (mm/kasan/report.c:489) 
[ 41.484905][ T69] ? kasan_addr_to_slab (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 ./include/linux/page-flags.h:481 mm/kasan/../slab.h:206 mm/kasan/common.c:38) 
[ 41.485171][ T69] kasan_report (mm/kasan/report.c:603) 
[ 41.485409][ T69] ? kobject_put (lib/kobject.c:729) 
[ 41.485668][ T69] kobject_put (lib/kobject.c:729) 
[ 41.485977][ T69] br_sysfs_delbr (net/bridge/br_sysfs_br.c:1086) 
[ 41.486256][ T69] br_dev_delete (net/bridge/br_if.c:396) 
[ 41.486503][ T69] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[ 41.486826][ T69] cleanup_net (net/core/net_namespace.c:628 (discriminator 2)) 
[ 41.487104][ T69] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 41.487401][ T69] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 41.487667][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 41.487913][ T69] ? process_one_work (kernel/workqueue.c:2609) 
[ 41.488217][ T69] process_one_work (kernel/workqueue.c:2638) 
[ 41.488547][ T69] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 41.488793][ T69] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 41.489082][ T69] ? assign_work (kernel/workqueue.c:1101) 
[ 41.489329][ T69] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 41.489575][ T69] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 41.489919][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 41.490189][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 41.490462][ T69] kthread (kernel/kthread.c:388) 
[ 41.490681][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 41.490927][ T69] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 41.491161][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 41.491472][ T69] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   41.511841][   T69] ------------[ cut here ]------------
| [   41.512162][   T69] refcount_t: underflow; use-after-free.
| [ 41.512533][ T69] WARNING: CPU: 3 PID: 69 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
| [   41.513069][   T69] Modules linked in:
[   41.513880][   T69] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   41.514597][   T69] Workqueue: netns cleanup_net
[ 41.514895][ T69] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
[ 41.515258][ T69] Code: f9 82 03 80 fb 01 0f 87 ee 02 b1 01 83 e3 01 0f 85 4d ff ff ff c6 05 9a f9 82 03 01 90 48 c7 c7 20 7a 42 87 e8 3e 05 2a ff 90 <0f> 0b 90 90 e9 2f ff ff ff 48 89 df e8 8c 68 a6 ff e9 b6 fe ff ff
All code
========
   0:	f9                   	stc
   1:	82                   	(bad)
   2:	03 80 fb 01 0f 87    	add    -0x78f0fe05(%rax),%eax
   8:	ee                   	out    %al,(%dx)
   9:	02 b1 01 83 e3 01    	add    0x1e38301(%rcx),%dh
   f:	0f 85 4d ff ff ff    	jne    0xffffffffffffff62
  15:	c6 05 9a f9 82 03 01 	movb   $0x1,0x382f99a(%rip)        # 0x382f9b6
  1c:	90                   	nop
  1d:	48 c7 c7 20 7a 42 87 	mov    $0xffffffff87427a20,%rdi
  24:	e8 3e 05 2a ff       	call   0xffffffffff2a0567
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	e9 2f ff ff ff       	jmp    0xffffffffffffff62
  33:	48 89 df             	mov    %rbx,%rdi
  36:	e8 8c 68 a6 ff       	call   0xffffffffffa668c7
  3b:	e9 b6 fe ff ff       	jmp    0xfffffffffffffef6

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	e9 2f ff ff ff       	jmp    0xffffffffffffff38
   9:	48 89 df             	mov    %rbx,%rdi
   c:	e8 8c 68 a6 ff       	call   0xffffffffffa6689d
  11:	e9 b6 fe ff ff       	jmp    0xfffffffffffffecc
[   41.516425][   T69] RSP: 0018:ffffc900004ffb98 EFLAGS: 00010282
[   41.516791][   T69] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8471056f
[   41.517266][   T69] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
[   41.517750][   T69] RBP: 0000000000000003 R08: 0000000000000000 R09: fffff5200009ff18
[   41.518213][   T69] R10: ffffc900004ff8c7 R11: 205d393654202020 R12: ffff888005e72000
[   41.518668][   T69] R13: ffff888005e72df8 R14: ffffc900004ffc98 R15: ffff888005e72bc0
[   41.519200][   T69] FS:  0000000000000000(0000) GS:ffff888035e00000(0000) knlGS:0000000000000000
[   41.519693][   T69] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   41.520042][   T69] CR2: 00007f7b272cd270 CR3: 000000001ed34005 CR4: 00000000001706f0
[   41.520479][   T69] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   41.520899][   T69] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   41.521357][   T69] Call Trace:
[   41.521561][   T69]  <TASK>
[ 41.521722][ T69] ? __warn (kernel/panic.c:677) 
[ 41.521949][ T69] ? refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
[ 41.522274][ T69] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[ 41.522543][ T69] ? vprintk_emit (kernel/printk/printk.c:2313) 
[ 41.522818][ T69] ? handle_bug (arch/x86/kernel/traps.c:238) 
[ 41.523079][ T69] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[ 41.523336][ T69] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[ 41.523633][ T69] ? desc_read (./arch/x86/include/asm/atomic64_64.h:20 ./include/linux/atomic/atomic-arch-fallback.h:2615 ./include/linux/atomic/atomic-long.h:79 ./include/linux/atomic/atomic-instrumented.h:3196 kernel/printk/printk_ringbuffer.c:534) 
[ 41.523872][ T69] ? refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
[ 41.524163][ T69] ? refcount_warn_saturate (lib/refcount.c:28 (discriminator 3)) 
[ 41.524451][ T69] br_sysfs_delbr (net/bridge/br_sysfs_br.c:1086) 
[ 41.524696][ T69] br_dev_delete (net/bridge/br_if.c:396) 
[ 41.524946][ T69] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[ 41.525228][ T69] cleanup_net (net/core/net_namespace.c:628 (discriminator 2)) 
[ 41.525489][ T69] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 41.525814][ T69] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 41.526120][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 41.526418][ T69] ? process_one_work (kernel/workqueue.c:2609) 
[ 41.526713][ T69] process_one_work (kernel/workqueue.c:2638) 
[ 41.527020][ T69] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 41.527289][ T69] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 41.527589][ T69] ? assign_work (kernel/workqueue.c:1101) 
[ 41.527878][ T69] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 41.528162][ T69] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 41.528642][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 41.528938][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 41.529231][ T69] kthread (kernel/kthread.c:388) 
[ 41.529468][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 41.529720][ T69] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 41.529955][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 41.530197][ T69] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   41.533240][   T69] ------------[ cut here ]------------
| [   41.533533][   T69] sysfs group 'bridge' not found for kobject 'br0'
| [ 41.533904][ T69] WARNING: CPU: 3 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   41.534418][   T69] Modules linked in:
[   41.535212][   T69] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   41.535940][   T69] Workqueue: netns cleanup_net
[ 41.536210][ T69] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 41.536558][ T69] Code: 89 d9 49 8b 14 24 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 01 00 75 45 48 8b 33 48 c7 c7 a0 a7 3c 87 e8 60 65 5e ff 90 <0f> 0b 90 90 48 83 c4 08 5b 5d 41 5c c3 cc cc cc cc e8 e9 c7 da ff
All code
========
   0:	89 d9                	mov    %ebx,%ecx
   2:	49 8b 14 24          	mov    (%r12),%rdx
   6:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   d:	fc ff df 
  10:	48 c1 e9 03          	shr    $0x3,%rcx
  14:	80 3c 01 00          	cmpb   $0x0,(%rcx,%rax,1)
  18:	75 45                	jne    0x5f
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 a7 3c 87 	mov    $0xffffffff873ca7a0,%rdi
  24:	e8 60 65 5e ff       	call   0xffffffffff5e6589
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	48 83 c4 08          	add    $0x8,%rsp
  32:	5b                   	pop    %rbx
  33:	5d                   	pop    %rbp
  34:	41 5c                	pop    %r12
  36:	c3                   	ret
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	e8 e9 c7 da ff       	call   0xffffffffffdac829

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	48 83 c4 08          	add    $0x8,%rsp
   8:	5b                   	pop    %rbx
   9:	5d                   	pop    %rbp
   a:	41 5c                	pop    %r12
   c:	c3                   	ret
   d:	cc                   	int3
   e:	cc                   	int3
   f:	cc                   	int3
  10:	cc                   	int3
  11:	e8 e9 c7 da ff       	call   0xffffffffffdac7ff
[   41.537634][   T69] RSP: 0018:ffffc900004ffba0 EFLAGS: 00010282
[   41.537958][   T69] RAX: 0000000000000000 RBX: ffffffff877be220 RCX: ffffffff8471056f
[   41.538375][   T69] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
[   41.538798][   T69] RBP: 0000000000000000 R08: 0000000000000000 R09: fffff5200009ff19
[   41.539218][   T69] R10: ffffc900004ff8cf R11: 205d393654202020 R12: ffff888005e72628
[   41.539643][   T69] R13: ffff888005e72df8 R14: ffffc900004ffc98 R15: ffff888005e72bc0
[   41.540065][   T69] FS:  0000000000000000(0000) GS:ffff888035e00000(0000) knlGS:0000000000000000
[   41.540585][   T69] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   41.541000][   T69] CR2: 00007f7b272cd270 CR3: 000000001ed34005 CR4: 00000000001706f0
[   41.541458][   T69] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   41.541881][   T69] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   41.542302][   T69] Call Trace:
[   41.542488][   T69]  <TASK>
[ 41.542653][ T69] ? __warn (kernel/panic.c:677) 
[ 41.542871][ T69] ? console_trylock (kernel/printk/printk.c:2659 kernel/printk/printk.c:2654) 
[ 41.543129][ T69] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 41.543403][ T69] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[ 41.543651][ T69] ? handle_bug (arch/x86/kernel/traps.c:238) 
[ 41.543881][ T69] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[ 41.544129][ T69] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[ 41.544394][ T69] ? desc_read (./arch/x86/include/asm/atomic64_64.h:20 ./include/linux/atomic/atomic-arch-fallback.h:2615 ./include/linux/atomic/atomic-long.h:79 ./include/linux/atomic/atomic-instrumented.h:3196 kernel/printk/printk_ringbuffer.c:534) 
[ 41.544684][ T69] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 41.545019][ T69] br_dev_delete (net/bridge/br_if.c:396) 
[ 41.545299][ T69] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[ 41.545632][ T69] cleanup_net (net/core/net_namespace.c:628 (discriminator 2)) 
[ 41.545886][ T69] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 41.546239][ T69] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 41.546499][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 41.546754][ T69] ? process_one_work (kernel/workqueue.c:2609) 
[ 41.547088][ T69] process_one_work (kernel/workqueue.c:2638) 
[ 41.547386][ T69] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 41.547650][ T69] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 41.547981][ T69] ? assign_work (kernel/workqueue.c:1101) 
[ 41.548270][ T69] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 41.548561][ T69] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 41.548930][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 41.549243][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 41.549556][ T69] kthread (kernel/kthread.c:388) 
[ 41.549790][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 41.550077][ T69] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 41.550343][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 41.550638][ T69] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   63.974491][   T69] ------------[ cut here ]------------
| [   63.974827][   T69] sysfs group 'bridge' not found for kobject 'br0'
| [ 63.975219][ T69] WARNING: CPU: 1 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   63.975733][   T69] Modules linked in:
[   63.976444][   T69] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   63.977246][   T69] Workqueue: netns cleanup_net
[ 63.977511][ T69] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 63.977840][ T69] Code: 89 d9 49 8b 14 24 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 01 00 75 45 48 8b 33 48 c7 c7 a0 a7 3c 87 e8 60 65 5e ff 90 <0f> 0b 90 90 48 83 c4 08 5b 5d 41 5c c3 cc cc cc cc e8 e9 c7 da ff
All code
========
   0:	89 d9                	mov    %ebx,%ecx
   2:	49 8b 14 24          	mov    (%r12),%rdx
   6:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   d:	fc ff df 
  10:	48 c1 e9 03          	shr    $0x3,%rcx
  14:	80 3c 01 00          	cmpb   $0x0,(%rcx,%rax,1)
  18:	75 45                	jne    0x5f
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 a7 3c 87 	mov    $0xffffffff873ca7a0,%rdi
  24:	e8 60 65 5e ff       	call   0xffffffffff5e6589
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	48 83 c4 08          	add    $0x8,%rsp
  32:	5b                   	pop    %rbx
  33:	5d                   	pop    %rbp
  34:	41 5c                	pop    %r12
  36:	c3                   	ret
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	e8 e9 c7 da ff       	call   0xffffffffffdac829

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	48 83 c4 08          	add    $0x8,%rsp
   8:	5b                   	pop    %rbx
   9:	5d                   	pop    %rbp
   a:	41 5c                	pop    %r12
   c:	c3                   	ret
   d:	cc                   	int3
   e:	cc                   	int3
   f:	cc                   	int3
  10:	cc                   	int3
  11:	e8 e9 c7 da ff       	call   0xffffffffffdac7ff
[   63.978943][   T69] RSP: 0018:ffffc900004ffba0 EFLAGS: 00010282
[   63.979302][   T69] RAX: 0000000000000000 RBX: ffffffff877be220 RCX: ffffffff8471056f
[   63.979766][   T69] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
[   63.980215][   T69] RBP: 0000000000000000 R08: 0000000000000000 R09: fffff5200009ff19
[   63.980675][   T69] R10: ffffc900004ff8cf R11: 205d393654202020 R12: ffff888009082628
[   63.981109][   T69] R13: ffff888009082df8 R14: ffffc900004ffc98 R15: ffff888009082bc0
[   63.981588][   T69] FS:  0000000000000000(0000) GS:ffff888035600000(0000) knlGS:0000000000000000
[   63.982082][   T69] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   63.982458][   T69] CR2: 000055e2f929303c CR3: 000000001ed34002 CR4: 00000000001706f0
[   63.982943][   T69] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   63.983400][   T69] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   63.983888][   T69] Call Trace:
[   63.984065][   T69]  <TASK>
[ 63.984243][ T69] ? __warn (kernel/panic.c:677) 
[ 63.984473][ T69] ? console_trylock (kernel/printk/printk.c:2659 kernel/printk/printk.c:2654) 
[ 63.984748][ T69] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 63.985034][ T69] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[ 63.985295][ T69] ? handle_bug (arch/x86/kernel/traps.c:238) 
[ 63.985538][ T69] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[ 63.985807][ T69] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[ 63.986083][ T69] ? desc_read (./arch/x86/include/asm/atomic64_64.h:20 ./include/linux/atomic/atomic-arch-fallback.h:2615 ./include/linux/atomic/atomic-long.h:79 ./include/linux/atomic/atomic-instrumented.h:3196 kernel/printk/printk_ringbuffer.c:534) 
[ 63.986341][ T69] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 63.986654][ T69] br_dev_delete (net/bridge/br_if.c:396) 
[ 63.986944][ T69] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[ 63.987239][ T69] cleanup_net (net/core/net_namespace.c:628 (discriminator 2)) 
[ 63.987497][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 63.987754][ T69] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 63.988040][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 63.988309][ T69] ? process_one_work (kernel/workqueue.c:2609) 
[ 63.988597][ T69] process_one_work (kernel/workqueue.c:2638) 
[ 63.988877][ T69] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 63.989122][ T69] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 63.989440][ T69] ? assign_work (kernel/workqueue.c:1101) 
[ 63.989718][ T69] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 63.989972][ T69] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 63.990341][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 63.990639][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 63.990927][ T69] kthread (kernel/kthread.c:388) 
[ 63.991144][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 63.991399][ T69] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 63.991663][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 63.991920][ T69] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [   86.443046][   T69] ------------[ cut here ]------------
| [   86.443353][   T69] sysfs group 'bridge' not found for kobject 'br0'
| [ 86.443735][ T69] WARNING: CPU: 0 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [   86.444215][   T69] Modules linked in:
[   86.445052][   T69] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   86.445765][   T69] Workqueue: netns cleanup_net
[ 86.446030][ T69] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 86.446392][ T69] Code: 89 d9 49 8b 14 24 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 01 00 75 45 48 8b 33 48 c7 c7 a0 a7 3c 87 e8 60 65 5e ff 90 <0f> 0b 90 90 48 83 c4 08 5b 5d 41 5c c3 cc cc cc cc e8 e9 c7 da ff
All code
========
   0:	89 d9                	mov    %ebx,%ecx
   2:	49 8b 14 24          	mov    (%r12),%rdx
   6:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   d:	fc ff df 
  10:	48 c1 e9 03          	shr    $0x3,%rcx
  14:	80 3c 01 00          	cmpb   $0x0,(%rcx,%rax,1)
  18:	75 45                	jne    0x5f
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 a7 3c 87 	mov    $0xffffffff873ca7a0,%rdi
  24:	e8 60 65 5e ff       	call   0xffffffffff5e6589
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	48 83 c4 08          	add    $0x8,%rsp
  32:	5b                   	pop    %rbx
  33:	5d                   	pop    %rbp
  34:	41 5c                	pop    %r12
  36:	c3                   	ret
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	e8 e9 c7 da ff       	call   0xffffffffffdac829

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	48 83 c4 08          	add    $0x8,%rsp
   8:	5b                   	pop    %rbx
   9:	5d                   	pop    %rbp
   a:	41 5c                	pop    %r12
   c:	c3                   	ret
   d:	cc                   	int3
   e:	cc                   	int3
   f:	cc                   	int3
  10:	cc                   	int3
  11:	e8 e9 c7 da ff       	call   0xffffffffffdac7ff
[   86.447460][   T69] RSP: 0018:ffffc900004ffba0 EFLAGS: 00010282
[   86.447833][   T69] RAX: 0000000000000000 RBX: ffffffff877be220 RCX: ffffffff8471056f
[   86.448306][   T69] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
[   86.448775][   T69] RBP: 0000000000000000 R08: 0000000000000000 R09: fffff5200009ff19
[   86.449216][   T69] R10: ffffc900004ff8cf R11: 205d393654202020 R12: ffff8880035d2628
[   86.449680][   T69] R13: ffff8880035d2df8 R14: ffffc900004ffc98 R15: ffff8880035d2bc0
[   86.450149][   T69] FS:  0000000000000000(0000) GS:ffff888035200000(0000) knlGS:0000000000000000
[   86.450653][   T69] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   86.451029][   T69] CR2: 00007fbbe53610e0 CR3: 000000001ed34006 CR4: 00000000001706f0
[   86.451489][   T69] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   86.451955][   T69] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   86.452435][   T69] Call Trace:
[   86.452651][   T69]  <TASK>
[ 86.452814][ T69] ? __warn (kernel/panic.c:677) 
[ 86.453078][ T69] ? console_trylock (kernel/printk/printk.c:2659 kernel/printk/printk.c:2654) 
[ 86.453377][ T69] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 86.453712][ T69] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[ 86.453984][ T69] ? handle_bug (arch/x86/kernel/traps.c:238) 
[ 86.454257][ T69] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[ 86.454526][ T69] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[ 86.454826][ T69] ? desc_read (./arch/x86/include/asm/atomic64_64.h:20 ./include/linux/atomic/atomic-arch-fallback.h:2615 ./include/linux/atomic/atomic-long.h:79 ./include/linux/atomic/atomic-instrumented.h:3196 kernel/printk/printk_ringbuffer.c:534) 
[ 86.455112][ T69] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 86.455419][ T69] br_dev_delete (net/bridge/br_if.c:396) 
[ 86.455715][ T69] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[ 86.456046][ T69] cleanup_net (net/core/net_namespace.c:628 (discriminator 2)) 
[ 86.456324][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 86.456585][ T69] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 86.456849][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 86.457094][ T69] ? process_one_work (kernel/workqueue.c:2609) 
[ 86.457366][ T69] process_one_work (kernel/workqueue.c:2638) 
[ 86.457637][ T69] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 86.457922][ T69] ? assign_work (kernel/workqueue.c:1101) 
[ 86.458169][ T69] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 86.458466][ T69] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 86.458876][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 86.459174][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 86.459491][ T69] kthread (kernel/kthread.c:388) 
[ 86.459753][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 86.460028][ T69] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 86.460297][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 86.460585][ T69] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [  109.120488][   T69] ------------[ cut here ]------------
| [  109.120817][   T69] sysfs group 'bridge' not found for kobject 'br0'
| [ 109.121192][ T69] WARNING: CPU: 0 PID: 69 at fs/sysfs/group.c:282 sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
| [  109.121742][   T69] Modules linked in:
[  109.122450][   T69] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  109.123254][   T69] Workqueue: netns cleanup_net
[ 109.123527][ T69] RIP: 0010:sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 109.123837][ T69] Code: 89 d9 49 8b 14 24 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 01 00 75 45 48 8b 33 48 c7 c7 a0 a7 3c 87 e8 60 65 5e ff 90 <0f> 0b 90 90 48 83 c4 08 5b 5d 41 5c c3 cc cc cc cc e8 e9 c7 da ff
All code
========
   0:	89 d9                	mov    %ebx,%ecx
   2:	49 8b 14 24          	mov    (%r12),%rdx
   6:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   d:	fc ff df 
  10:	48 c1 e9 03          	shr    $0x3,%rcx
  14:	80 3c 01 00          	cmpb   $0x0,(%rcx,%rax,1)
  18:	75 45                	jne    0x5f
  1a:	48 8b 33             	mov    (%rbx),%rsi
  1d:	48 c7 c7 a0 a7 3c 87 	mov    $0xffffffff873ca7a0,%rdi
  24:	e8 60 65 5e ff       	call   0xffffffffff5e6589
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	48 83 c4 08          	add    $0x8,%rsp
  32:	5b                   	pop    %rbx
  33:	5d                   	pop    %rbp
  34:	41 5c                	pop    %r12
  36:	c3                   	ret
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	e8 e9 c7 da ff       	call   0xffffffffffdac829

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	48 83 c4 08          	add    $0x8,%rsp
   8:	5b                   	pop    %rbx
   9:	5d                   	pop    %rbp
   a:	41 5c                	pop    %r12
   c:	c3                   	ret
   d:	cc                   	int3
   e:	cc                   	int3
   f:	cc                   	int3
  10:	cc                   	int3
  11:	e8 e9 c7 da ff       	call   0xffffffffffdac7ff
[  109.124973][   T69] RSP: 0018:ffffc900004ffba0 EFLAGS: 00010282
[  109.125379][   T69] RAX: 0000000000000000 RBX: ffffffff877be220 RCX: ffffffff8471056f
[  109.125873][   T69] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
[  109.126365][   T69] RBP: 0000000000000000 R08: 0000000000000000 R09: fffff5200009ff19
[  109.126827][   T69] R10: ffffc900004ff8cf R11: 205d393654202020 R12: ffff888008172628
[  109.127335][   T69] R13: ffff888008172df8 R14: ffffc900004ffc98 R15: ffff888008172bc0
[  109.127855][   T69] FS:  0000000000000000(0000) GS:ffff888035200000(0000) knlGS:0000000000000000
[  109.128396][   T69] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  109.128836][   T69] CR2: 00007f9f79900270 CR3: 000000001ed34002 CR4: 00000000001706f0
[  109.129344][   T69] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  109.129848][   T69] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  109.130331][   T69] Call Trace:
[  109.130620][   T69]  <TASK>
[ 109.130934][ T69] ? __warn (kernel/panic.c:677) 
[ 109.131243][ T69] ? console_trylock (kernel/printk/printk.c:2659 kernel/printk/printk.c:2654) 
[ 109.131615][ T69] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 109.132023][ T69] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[ 109.132398][ T69] ? handle_bug (arch/x86/kernel/traps.c:238) 
[ 109.132761][ T69] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[ 109.133049][ T69] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[ 109.133356][ T69] ? desc_read (./arch/x86/include/asm/atomic64_64.h:20 ./include/linux/atomic/atomic-arch-fallback.h:2615 ./include/linux/atomic/atomic-long.h:79 ./include/linux/atomic/atomic-instrumented.h:3196 kernel/printk/printk_ringbuffer.c:534) 
[ 109.133643][ T69] ? sysfs_remove_group (fs/sysfs/group.c:282 (discriminator 1)) 
[ 109.133936][ T69] br_dev_delete (net/bridge/br_if.c:396) 
[ 109.134214][ T69] br_net_exit_batch_rtnl (net/bridge/br.c:369) 
[ 109.134523][ T69] cleanup_net (net/core/net_namespace.c:628 (discriminator 2)) 
[ 109.134797][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 109.135093][ T69] ? __pfx_cleanup_net (net/core/net_namespace.c:581) 
[ 109.135372][ T69] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5725) 
[ 109.135664][ T69] ? process_one_work (kernel/workqueue.c:2609) 
[ 109.135960][ T69] process_one_work (kernel/workqueue.c:2638) 
[ 109.136261][ T69] ? __pfx_process_one_work (kernel/workqueue.c:2542) 
[ 109.136601][ T69] ? assign_work (kernel/workqueue.c:1101) 
[ 109.136859][ T69] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 109.137127][ T69] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 109.137492][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 109.137808][ T69] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 109.138129][ T69] kthread (kernel/kthread.c:388) 
[ 109.138344][ T69] ? __pfx_kthread (kernel/kthread.c:341) 
[ 109.138628][ T69] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 109.138888][ T69] ? __pfx_kthread (kernel/kthread.c:341) 


Finger prints:
dump_stack_lvl:print_report:kasan_report:kobject_put
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