======================================
| [   30.132550][   T72] ==================================================================
| [   30.132936][   T72] BUG: KASAN: slab-use-after-free in kobject_put (lib/kobject.c:733)
| [   30.133263][   T72] Read of size 1 at addr ffff888008d5169c by task kworker/u16:1/72
| [   30.133553][   T72]
[   30.133659][   T72] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   30.133662][   T72] Workqueue: netns cleanup_net
[   30.133672][   T72] Call Trace:
[   30.133674][   T72]  <TASK>
[   30.133678][   T72]  dump_stack_lvl (lib/dump_stack.c:123)
[   30.133684][   T72]  print_address_description.constprop.0 (mm/kasan/report.c:379)
[   30.133693][   T72]  ? kobject_put (lib/kobject.c:733)
[   30.133697][   T72]  print_report (mm/kasan/report.c:483)
[   30.133703][   T72]  ? kobject_put (lib/kobject.c:733)
[   30.133706][   T72]  ? kasan_addr_to_slab (./include/linux/mm.h:1245 mm/kasan/../slab.h:191 mm/kasan/common.c:47)
[   30.133711][   T72]  ? kobject_put (lib/kobject.c:733)
[   30.133714][   T72]  kasan_report (mm/kasan/report.c:597)
[   30.133719][   T72]  ? kobject_put (lib/kobject.c:733)
[   30.133726][   T72]  kobject_put (lib/kobject.c:733)
[   30.133729][   T72]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[   30.133735][   T72]  ? dev_ingress_queue_create (net/core/dev.c:12299)
[   30.133739][   T72]  ? generic_xdp_install (net/core/dev.c:11630)
[   30.133741][   T72]  ? __lock_release (kernel/locking/lockdep.c:5536)
[   30.133749][   T72]  ? bond_net_exit_rtnl (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:897 ./include/net/netns/generic.h:48 drivers/net/bonding/bond_main.c:6462)
[   30.133758][   T72]  ops_undo_list (net/core/net_namespace.c:190 net/core/net_namespace.c:248)
[   30.133763][   T72]  ? netns_get (net/core/net_namespace.c:223)
[   30.133766][   T72]  ? cleanup_net (./include/linux/list.h:191 net/core/net_namespace.c:693)
[   30.133771][   T72]  cleanup_net (net/core/net_namespace.c:698)
[   30.133775][   T72]  ? net_passive_dec (net/core/net_namespace.c:660)
[   30.133780][   T72]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[   30.133787][   T72]  process_one_work (kernel/workqueue.c:3268)
[   30.133795][   T72]  ? pwq_dec_nr_in_flight (kernel/workqueue.c:3165)
[   30.133801][   T72]  ? assign_work (kernel/workqueue.c:1206)
[   30.133805][   T72]  worker_thread (kernel/workqueue.c:3340 kernel/workqueue.c:3427)
[   30.133811][   T72]  ? rescuer_thread (kernel/workqueue.c:3373)
[   30.133814][   T72]  kthread (kernel/kthread.c:463)
[   30.133819][   T72]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[   30.133822][   T72]  ? ret_from_fork (arch/x86/kernel/process.c:157)
[   30.133830][   T72]  ? __lock_release (kernel/locking/lockdep.c:5536)
[   30.133834][   T72]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[   30.133837][   T72]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[   30.133840][   T72]  ret_from_fork (arch/x86/kernel/process.c:164)
[   30.133843][   T72]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[   30.133846][   T72]  ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
| [   30.156506][   T72] refcount_t: underflow; use-after-free.
| [   30.156738][   T72] WARNING: CPU: 2 PID: 72 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [   30.157149][   T72] Modules linked in:
| [   30.158760][   T72] Tainted: [B]=BAD_PAGE
[   30.159727][   T72] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   30.160023][   T72] Workqueue: netns cleanup_net
[   30.160270][   T72] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[   30.160564][   T72] Code: a2 b5 02 80 fb 01 0f 87 db 6e d8 fe 83 e3 01 0f 85 51 ff ff ff c6 05 c2 a2 b5 02 01 90 48 c7 c7 60 a8 a5 91 e8 72 c3 17 ff 90 <0f> 0b 90 90 e9 33 ff ff ff 48 89 df e8 20 69 a0 ff e9 ba fe ff ff
All code
========
   0:	a2 b5 02 80 fb 01 0f 	movabs %al,0xdb870f01fb8002b5
   7:	87 db 
   9:	6e                   	outsb  %ds:(%rsi),(%dx)
   a:	d8 fe                	fdivr  %st(6),%st
   c:	83 e3 01             	and    $0x1,%ebx
   f:	0f 85 51 ff ff ff    	jne    0xffffffffffffff66
  15:	c6 05 c2 a2 b5 02 01 	movb   $0x1,0x2b5a2c2(%rip)        # 0x2b5a2de
  1c:	90                   	nop
  1d:	48 c7 c7 60 a8 a5 91 	mov    $0xffffffff91a5a860,%rdi
  24:	e8 72 c3 17 ff       	call   0xffffffffff17c39b
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	e9 33 ff ff ff       	jmp    0xffffffffffffff66
  33:	48 89 df             	mov    %rbx,%rdi
  36:	e8 20 69 a0 ff       	call   0xffffffffffa0695b
  3b:	e9 ba fe ff ff       	jmp    0xfffffffffffffefa

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	e9 33 ff ff ff       	jmp    0xffffffffffffff3c
   9:	48 89 df             	mov    %rbx,%rdi
   c:	e8 20 69 a0 ff       	call   0xffffffffffa06931
  11:	e9 ba fe ff ff       	jmp    0xfffffffffffffed0
[   30.161168][   T72] RSP: 0000:ffffc900004d7a08 EFLAGS: 00010282
[   30.161395][   T72] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   30.161662][   T72] RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000001
[   30.161958][   T72] RBP: 0000000000000003 R08: 0000000000000000 R09: fffffbfff247e134
[   30.162225][   T72] R10: 0000000000000003 R11: ffffc900004d7580 R12: 0000000000000001
[   30.162531][   T72] R13: dffffc0000000000 R14: dead000000000122 R15: dead000000000100
[   30.162797][   T72] FS:  0000000000000000(0000) GS:ffff8880a2a81000(0000) knlGS:0000000000000000
[   30.163107][   T72] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   30.163332][   T72] CR2: 00007f789bd71b30 CR3: 0000000011f35005 CR4: 0000000000772ef0
[   30.163604][   T72] PKRU: 55555554
[   30.163842][   T72] Call Trace:
[   30.163996][   T72]  <TASK>
[   30.164154][   T72]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[   30.164402][   T72]  ? dev_ingress_queue_create (net/core/dev.c:12299)
[   30.164628][   T72]  ? generic_xdp_install (net/core/dev.c:11630)
[   30.164958][   T72]  ? __lock_release (kernel/locking/lockdep.c:5536)
[   30.165180][   T72]  ? bond_net_exit_rtnl (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:897 ./include/net/netns/generic.h:48 drivers/net/bonding/bond_main.c:6462)
[   30.165463][   T72]  ops_undo_list (net/core/net_namespace.c:190 net/core/net_namespace.c:248)
[   30.165739][   T72]  ? netns_get (net/core/net_namespace.c:223)
[   30.165990][   T72]  ? cleanup_net (./include/linux/list.h:191 net/core/net_namespace.c:693)
[   30.166211][   T72]  cleanup_net (net/core/net_namespace.c:698)
[   30.166442][   T72]  ? net_passive_dec (net/core/net_namespace.c:660)
[   30.166639][   T72]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[   30.166933][   T72]  process_one_work (kernel/workqueue.c:3268)
[   30.167140][   T72]  ? pwq_dec_nr_in_flight (kernel/workqueue.c:3165)
[   30.167338][   T72]  ? assign_work (kernel/workqueue.c:1206)
[   30.167533][   T72]  worker_thread (kernel/workqueue.c:3340 kernel/workqueue.c:3427)
[   30.167753][   T72]  ? rescuer_thread (kernel/workqueue.c:3373)
[   30.167949][   T72]  kthread (kernel/kthread.c:463)
[   30.168132][   T72]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[   30.168337][   T72]  ? ret_from_fork (arch/x86/kernel/process.c:157)
[   30.168579][   T72]  ? __lock_release (kernel/locking/lockdep.c:5536)
[   30.168790][   T72]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[   30.168997][   T72]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[   30.169214][   T72]  ret_from_fork (arch/x86/kernel/process.c:164)
[   30.169490][   T72]  ? kthread_is_per_cpu (kernel/kthread.c:412)


Finger prints:
refcount_warn_saturate:netdev_run_todo:ops_undo_list:cleanup_net:process_one_work
print_report:kasan_report:kobject_put:netdev_run_todo:ops_undo_list