INFO: task kworker/u8:2:5754 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2    state:D stack:21992 pid:5754  tgid:5754  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 addrconf_verify_work+0x19/0x30
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
locks held by kworker/u8:0/12: 4, last CPU#1:
 #0: ffff8881192bf140 ((wq_completion)krds_cp_wq#16/0){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000117c40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff88810d6cf980 (&tc->t_conn_path_lock){+.+.}-{4:4}, at: rds_tcp_conn_path_connect+0x1cc/0x920
 #3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __inet_dev_addr_type+0x159/0x560
locks held by kworker/u8:1/13: 3, last CPU#0:
 #0: ffff888115545940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000127c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff88812103bb20 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160
locks held by khungtaskd/35: 1, last CPU#1:
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by kworker/u9:3/67: 3, last CPU#0:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90001797c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff8881bc3aa258 (&devlink->lock_key#4){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40
locks held by udevd/5042: 2, last CPU#1:
 #0: ffff88816da04460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff8881606b0e98 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_unlinkat+0x2a7/0x610
locks held by dhcpcd/5338: 1, on CPU#0:
 #0: ffffffff902526c0 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x249/0x390
locks held by getty/5420: 2, on CPU#1:
 #0: ffff8881181270a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034832e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by syz-executor/5578: 2, last CPU#0:
 #0: ffff8881b7c536b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240
locks held by kworker/u8:2/5754: 3, on CPU#1:
 #0: ffff888114d17940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900046ffc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902526c0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
locks held by syz-executor/8071: 1, on CPU#0:
 #0: ffffffff902526c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
locks held by kworker/u10:8/18054: 3, last CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90008847c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff888021dd3258 (&devlink->lock_key#8){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40
locks held by kworker/u10:16/18065: 3, last CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000834fc40 ((work_completion)(&(&ipvs->defense_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff8ebe98f0 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20
locks held by kworker/1:1/1568: 4, last CPU#1:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000a87c40 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffc90000a87770 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_atomic_helper_dirtyfb+0x106/0xfd0
 #3: ffffc90000a87798 (crtc_ww_class_mutex){+.+.}-{4:4}, at: drm_atomic_helper_dirtyfb+0x106/0xfd0
locks held by kworker/u8:8/8101: 3, last CPU#1:
 #0: ffff88810c222140 ((wq_completion)krds_cp_wq#0/0){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900070e7c40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550
locks held by kworker/0:0/9810: 2, last CPU#0:
 #0: ffff888100069d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900045c7c40 ((work_completion)(&(&gc_work->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
locks held by kworker/u9:8/10905: 3, last CPU#0:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffff88823c624408 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: taprio_dequeue+0x26/0x540
locks held by kworker/u8:4/13553: 4, last CPU#0:
 #0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000439fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff90243e48 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810
 #3: ffffffff902526c0 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xd0/0x760
locks held by syz-executor/13554: 1, on CPU#0:
 #0: ffffffff902526c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
locks held by kworker/u10:1/13569: 3, last CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90004e37c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff88811699a258 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40
locks held by kworker/u10:4/13715: 3, last CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000630fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff8881bc3aa258 (&devlink->lock_key#4){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40
locks held by kworker/u10:9/13730: 5, last CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000361fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff88816d679258 (&devlink->lock_key#5){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40
 #3: ffff88823c63bb20 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160
 #4: ffff88823c624408 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0
locks held by kworker/u8:7/13737: 3, last CPU#1:
 #0: ffff8881ab3c3140 ((wq_completion)krds_cp_wq#18/0){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900034f7c40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff8881a6345280 (&tc->t_conn_path_lock){+.+.}-{4:4}, at: rds_tcp_conn_path_connect+0x1cc/0x920
locks held by syz-executor/13740: 1, on CPU#0:
 #0: ffffffff902526c0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/13753: 1, last CPU#1:
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550
locks held by syz-executor/13755: 1, on CPU#0:
 #0: ffffffff902526c0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by udevd/13765: 1, last CPU#1:
 #0: ffff8881096bd038 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0
locks held by syz-executor/13769: 4, last CPU#1:
 #0: ffff888118264460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff8881148dde20 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x200/0x370
 #2: ffffffff8f4f0f78 (tomoyo_ss){.+.+}-{0:0}, at: start_this_handle+0x1fbf/0x2200
 #3: ffff88823c63bb20 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17d/0x390
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9810 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events_power_efficient gc_worker
RIP: 0010:native_apic_msr_write+0x39/0x50
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc 89 f6 31 d2 e9 26 6d a6 03 66 0f 1f 44 00
RSP: 0018:ffffc90000007cf0 EFLAGS: 00000046
RAX: 0000000000000076 RBX: ffff888121023c80 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 0000000000000076 RDI: 0000000000000838
RBP: ffffc90000007dc0 R08: 0000000000000100 R09: 0000000000000001
R10: 0000000000000003 R11: ffffffff81754510 R12: 0000000000000076
R13: dffffc0000000000 R14: 000000000fffea30 R15: 0000000000000020
FS:  0000000000000000(0000) GS:ffff88818d6d2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe0b3e361a0 CR3: 000000001dd1c000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lapic_next_event+0x11/0x20
 clockevents_program_event+0x385/0x630
 __hrtimer_rearm_deferred+0x36c/0x4b0
 irqentry_exit+0x8d3/0x910
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80
Code: f7 e8 8d 33 bc f5 f7 c3 00 02 00 00 74 05 e8 50 77 e8 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 94 42 ad f5 65 48 8b 05 0c 41 ad 07 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc90000007f18 EFLAGS: 00000206
RAX: 0000000000000002 RBX: 0000000000000283 RCX: 8000000000000101
RDX: 0000000000000002 RSI: ffffffff8e475fa2 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff907a327f R09: 1ffffffff20f464f
R10: dffffc0000000000 R11: fffffbfff20f4650 R12: 0000000000000006
R13: 0000000000000008 R14: ffff888121028280 R15: 0000000000000020
 handle_softirqs+0x226/0x860
 __irq_exit_rcu+0xcb/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:seqcount_lockdep_reader_access+0xed/0x100
Code: 00 75 11 e8 35 77 c7 f7 4d 85 f6 75 16 e8 2b 77 c7 f7 eb 15 e8 24 77 c7 f7 e8 2f 91 e4 01 4d 85 f6 74 ea e8 15 77 c7 f7 fb 5b <41> 5e e9 bc 95 e7 01 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90
RSP: 0018:ffffc900045c7970 EFLAGS: 00000293
RAX: ffffffff8a00539b RBX: 0000000000000001 RCX: ffff88811390bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900045c7ad0 R08: ffffffff907a327f R09: 1ffffffff20f464f
R10: dffffc0000000000 R11: fffffbfff20f4650 R12: dffffc0000000000
R13: ffffffff818f9aba R14: 0000000000000200 R15: 0000000000005323
 gc_worker+0x31b/0x1890
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
