======================================
| [ 1184.247755][   T70] ==================================================================
| [ 1184.248084][   T70] BUG: KASAN: slab-use-after-free in kobject_put (lib/kobject.c:733)
| [ 1184.248370][   T70] Read of size 1 at addr ffff888010e446ac by task kworker/u16:1/70
| [ 1184.248627][   T70]
[ 1184.248720][   T70] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1184.248723][   T70] Workqueue: netns cleanup_net
[ 1184.248739][   T70] Call Trace:
[ 1184.248743][   T70]  <TASK>
[ 1184.248747][   T70]  dump_stack_lvl (lib/dump_stack.c:123)
[ 1184.248754][   T70]  print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 1184.248764][   T70]  ? kobject_put (lib/kobject.c:733)
[ 1184.248768][   T70]  print_report (mm/kasan/report.c:483)
[ 1184.248771][   T70]  ? kobject_put (lib/kobject.c:733)
[ 1184.248774][   T70]  ? kasan_addr_to_slab (./include/linux/mm.h:1245 mm/kasan/../slab.h:191 mm/kasan/common.c:47)
[ 1184.248778][   T70]  ? kobject_put (lib/kobject.c:733)
[ 1184.248781][   T70]  kasan_report (mm/kasan/report.c:597)
[ 1184.248784][   T70]  ? kobject_put (lib/kobject.c:733)
[ 1184.248790][   T70]  kobject_put (lib/kobject.c:733)
[ 1184.248794][   T70]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[ 1184.248802][   T70]  ? rtnl_is_locked (net/core/rtnetlink.c:169)
[ 1184.248810][   T70]  ? dev_ingress_queue_create (net/core/dev.c:12299)
[ 1184.248815][   T70]  ? generic_xdp_install (net/core/dev.c:11630)
[ 1184.248826][   T70]  ops_undo_list (net/core/net_namespace.c:190 net/core/net_namespace.c:248)
[ 1184.248833][   T70]  ? netns_get (net/core/net_namespace.c:223)
[ 1184.248836][   T70]  ? cleanup_net (./include/linux/list.h:191 net/core/net_namespace.c:693)
[ 1184.248841][   T70]  cleanup_net (net/core/net_namespace.c:698)
[ 1184.248845][   T70]  ? net_passive_dec (net/core/net_namespace.c:660)
[ 1184.248849][   T70]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[ 1184.248860][   T70]  process_one_work (kernel/workqueue.c:3268)
[ 1184.248870][   T70]  ? pwq_dec_nr_in_flight (kernel/workqueue.c:3165)
[ 1184.248876][   T70]  ? assign_work (kernel/workqueue.c:1206)
[ 1184.248880][   T70]  worker_thread (kernel/workqueue.c:3340 kernel/workqueue.c:3427)
[ 1184.248886][   T70]  ? rescuer_thread (kernel/workqueue.c:3373)
[ 1184.248889][   T70]  kthread (kernel/kthread.c:463)
[ 1184.248894][   T70]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[ 1184.248897][   T70]  ? ret_from_fork (arch/x86/kernel/process.c:157)
[ 1184.248905][   T70]  ? __lock_release (kernel/locking/lockdep.c:5536)
[ 1184.248912][   T70]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[ 1184.248915][   T70]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[ 1184.248921][   T70]  ret_from_fork (arch/x86/kernel/process.c:164)
[ 1184.248925][   T70]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[ 1184.248928][   T70]  ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
| [ 1184.267596][   T70] refcount_t: underflow; use-after-free.
| [ 1184.267831][   T70] WARNING: CPU: 2 PID: 70 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [ 1184.268191][   T70] Modules linked in: act_gact cls_flower vxlan ip6_udp_tunnel udp_tunnel bridge stp llc 8021q sch_ingress vrf veth
| [ 1184.269022][   T70] Tainted: [B]=BAD_PAGE
[ 1184.269182][   T70] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1184.269403][   T70] Workqueue: netns cleanup_net
[ 1184.269603][   T70] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[ 1184.269861][   T70] Code: 7d 93 02 80 fb 01 0f 87 bb 99 d9 fe 83 e3 01 0f 85 51 ff ff ff c6 05 a8 7d 93 02 01 90 48 c7 c7 60 8d a5 9a e8 32 bf 18 ff 90 <0f> 0b 90 90 e9 33 ff ff ff 48 89 df e8 b0 63 a1 ff e9 ba fe ff ff
All code
========
   0:	7d 93                	jge    0xffffffffffffff95
   2:	02 80 fb 01 0f 87    	add    -0x78f0fe05(%rax),%al
   8:	bb 99 d9 fe 83       	mov    $0x83fed999,%ebx
   d:	e3 01                	jrcxz  0x10
   f:	0f 85 51 ff ff ff    	jne    0xffffffffffffff66
  15:	c6 05 a8 7d 93 02 01 	movb   $0x1,0x2937da8(%rip)        # 0x2937dc4
  1c:	90                   	nop
  1d:	48 c7 c7 60 8d a5 9a 	mov    $0xffffffff9aa58d60,%rdi
  24:	e8 32 bf 18 ff       	call   0xffffffffff18bf5b
  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 b0 63 a1 ff       	call   0xffffffffffa163eb
  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 b0 63 a1 ff       	call   0xffffffffffa163c1
  11:	e9 ba fe ff ff       	jmp    0xfffffffffffffed0
[ 1184.270491][   T70] RSP: 0018:ffffc900004b7a08 EFLAGS: 00010282
[ 1184.270745][   T70] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 1184.271072][   T70] RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000001
[ 1184.271354][   T70] RBP: 0000000000000003 R08: 0000000000000000 R09: fffffbfff367e134
[ 1184.271622][   T70] R10: 0000000000000003 R11: ffffc900004b7580 R12: 0000000000000001
[ 1184.271991][   T70] R13: dffffc0000000000 R14: dead000000000122 R15: dead000000000100
[ 1184.272288][   T70] FS:  0000000000000000(0000) GS:ffff888099af2000(0000) knlGS:0000000000000000
[ 1184.272623][   T70] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1184.272882][   T70] CR2: 00007fda64d3e2a8 CR3: 000000000fadb006 CR4: 0000000000772ef0
[ 1184.273173][   T70] PKRU: 55555554
[ 1184.273332][   T70] Call Trace:
[ 1184.273487][   T70]  <TASK>
[ 1184.273594][   T70]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[ 1184.273809][   T70]  ? rtnl_is_locked (net/core/rtnetlink.c:169)
[ 1184.274086][   T70]  ? dev_ingress_queue_create (net/core/dev.c:12299)
[ 1184.274341][   T70]  ? generic_xdp_install (net/core/dev.c:11630)
[ 1184.274538][   T70]  ops_undo_list (net/core/net_namespace.c:190 net/core/net_namespace.c:248)
[ 1184.274756][   T70]  ? netns_get (net/core/net_namespace.c:223)
[ 1184.274960][   T70]  ? cleanup_net (./include/linux/list.h:191 net/core/net_namespace.c:693)
[ 1184.275178][   T70]  cleanup_net (net/core/net_namespace.c:698)
[ 1184.275379][   T70]  ? net_passive_dec (net/core/net_namespace.c:660)
[ 1184.275578][   T70]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[ 1184.275791][   T70]  process_one_work (kernel/workqueue.c:3268)
[ 1184.276018][   T70]  ? pwq_dec_nr_in_flight (kernel/workqueue.c:3165)
[ 1184.276255][   T70]  ? assign_work (kernel/workqueue.c:1206)
[ 1184.276451][   T70]  worker_thread (kernel/workqueue.c:3340 kernel/workqueue.c:3427)
[ 1184.276655][   T70]  ? rescuer_thread (kernel/workqueue.c:3373)
[ 1184.276866][   T70]  kthread (kernel/kthread.c:463)
[ 1184.277072][   T70]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[ 1184.277273][   T70]  ? ret_from_fork (arch/x86/kernel/process.c:157)
[ 1184.277484][   T70]  ? __lock_release (kernel/locking/lockdep.c:5536)
[ 1184.277714][   T70]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[ 1184.277932][   T70]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[ 1184.278141][   T70]  ret_from_fork (arch/x86/kernel/process.c:164)
[ 1184.278356][   T70]  ? 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