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ODEBUG: free active (active state 0) object: ffff8880591e4278 object type: timer_list hint: br_ip6_multicast_port_query_expired+0x0/0x20 net/bridge/br_private.h:1293
WARNING: lib/debugobjects.c:629 at debug_print_object+0x18e/0x2a0 lib/debugobjects.c:629, CPU#1: kworker/u32:15/7551
Modules linked in:
CPU: 1 UID: 0 PID: 7551 Comm: kworker/u32:15 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:debug_print_object+0x19b/0x2a0 lib/debugobjects.c:629
Code: b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4f 48 8d 3d f2 16 e0 0b 41 56 48 8b 14 dd c0 4b 1c 8c 4c 89 e6 <67> 48 0f b9 3a 58 83 05 6c b4 d5 0b 01 48 83 c4 18 5b 5d 41 5c 41
RSP: 0018:ffffc900006a0be8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffffffff8c1c4b00 RSI: ffffffff8c1c4720 RDI: ffffffff90e26560
RBP: 0000000000000001 R08: ffff8880591e4278 R09: ffffffff8bb2c760
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8c1c4720
R13: ffffffff8bb2c7a0 R14: ffffffff8a6520c0 R15: ffffc900006a0ce8
FS:  0000000000000000(0000) GS:ffff8880d646d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f61d4d0cd50 CR3: 000000005da5c000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000007800 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
 debug_check_no_obj_freed+0x4da/0x630 lib/debugobjects.c:1146
 slab_free_hook mm/slub.c:2620 [inline]
 slab_free mm/slub.c:6250 [inline]
 kfree+0x3d0/0x6c0 mm/slub.c:6565
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1f7/0x640 lib/kobject.c:737
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__kfree_rcu_sheaf+0xf2/0x710 mm/slub.c:5971
Code: e8 53 96 1f 09 41 89 c6 83 f8 07 0f 87 17 05 00 00 4a 03 1c f5 20 69 1d 8e 4c 8b 73 48 4d 85 f6 0f 84 a5 01 00 00 41 8b 46 18 <8d> 50 01 41 89 56 18 4d 89 64 c6 20 3b 55 2c 0f 83 f7 01 00 00 48
RSP: 0018:ffffc900065b7438 EFLAGS: 00000286
RAX: 000000000000001b RBX: ffff88806a53f8f8 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8c1c3980 RDI: ffffffff8c1c39c0
RBP: ffff88801b8428c0 R08: 000000000129f5ef R09: 000000000000002c
R10: 0000000000000200 R11: 0000000000000000 R12: ffff88802c45b580
R13: ffff88802935a500 R14: ffff88801c3c1800 R15: 000000000000000a
 kfree_rcu_sheaf mm/slab_common.c:1608 [inline]
 kvfree_call_rcu+0x1be/0x4f0 mm/slab_common.c:1957
 sctp_inet6addr_event+0x429/0x910 net/sctp/ipv6.c:115
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 atomic_notifier_call_chain+0x71/0x1c0 kernel/notifier.c:223
 addrconf_ifdown.isra.0+0xe85/0x1b70 net/ipv6/addrconf.c:3990
 addrconf_notify+0x4a3/0x1ba0 net/ipv6/addrconf.c:3788
 notifier_call_chain+0x99/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 netif_close_many+0x319/0x630 net/core/dev.c:1805
 unregister_netdevice_many_notify+0x840/0x24f0 net/core/dev.c:12391
 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
 ops_undo_list+0x8ff/0xab0 net/core/net_namespace.c:248
 cleanup_net+0x499/0x920 net/core/net_namespace.c:702
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
 process_scheduled_works kernel/workqueue.c:3397 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	b8 00 00 00 00       	mov    $0x0,%eax
   5:	00 fc                	add    %bh,%ah
   7:	ff                   	lcall  (bad)
   8:	df 48 89             	fisttps -0x77(%rax)
   b:	fa                   	cli
   c:	48 c1 ea 03          	shr    $0x3,%rdx
  10:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  14:	75 4f                	jne    0x65
  16:	48 8d 3d f2 16 e0 0b 	lea    0xbe016f2(%rip),%rdi        # 0xbe0170f
  1d:	41 56                	push   %r14
  1f:	48 8b 14 dd c0 4b 1c 	mov    -0x73e3b440(,%rbx,8),%rdx
  26:	8c
  27:	4c 89 e6             	mov    %r12,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	58                   	pop    %rax
  30:	83 05 6c b4 d5 0b 01 	addl   $0x1,0xbd5b46c(%rip)        # 0xbd5b4a3
  37:	48 83 c4 18          	add    $0x18,%rsp
  3b:	5b                   	pop    %rbx
  3c:	5d                   	pop    %rbp
  3d:	41 5c                	pop    %r12
  3f:	41                   	rex.B