INFO: task kworker/u8:3:5647 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3    state:D stack:23624 pid:5647  tgid:5647  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: 2, last CPU#0:
 #0: ffff88811335e940
 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
locks held by kworker/u8:1/13: 4, last CPU#1:
 #0: ffff88811fd93940 ((wq_completion)krds_cp_wq#1/4){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000127c40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff888116e28680 (&tc->t_conn_path_lock){+.+.}-{4:4}, at: rds_tcp_conn_path_connect+0x1cc/0x920
 #3: ffff88810bf98260 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: __inet6_bind+0x301/0xf30
locks held by khungtaskd/34: 1, last CPU#1:
 #0: ffffffff8ed5c760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by kworker/u10:5/995: 3, last CPU#0:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000700fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff88801d8ee258
 (&devlink->lock_key#5){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40
locks held by kworker/u10:8/1122: 2, on CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900076ffc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
locks held by kworker/0:4/5007: 3, on CPU#0:
 #0: ffff888100069d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc9000fcafc40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902517c0 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xac/0x1110
locks held by getty/5419: 2, on CPU#1:
 #0: ffff8881132de0a0 (&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/5583: 2, last CPU#0:
 #0: ffff888172a7b6b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0
 #1: ffffffff8ed5c760 (rcu_read_lock){....}-{1:3}, at: is_module_text_address+0x1d/0x1e0
locks held by kworker/u8:3/5647: 3, on CPU#0:
 #0: ffff888111fa8940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
