INFO: task kworker/0:4:5672 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:4     state:D stack:21352 pid:5672  tgid:5672  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient reg_check_chans_work
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7bf/0x1550
 reg_check_chans_work+0xac/0x1110
 process_scheduled_works+0xa8e/0x14e0
 worker_thread+0xa47/0xfb0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
3 locks held by kworker/u9:0/26:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90000a17c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff9002dec0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by kworker/u9:1/28:
1 lock held by khungtaskd/34:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:3/82:
3 locks held by kworker/u9:4/83:
4 locks held by kworker/u9:5/4244:
1 lock held by dhcpcd/5355:
 #0: ffffffff9002dec0 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65e/0xdf0
2 locks held by getty/5438:
 #0: ffff8881150da0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
4 locks held by kworker/u8:3/5663:
3 locks held by kworker/u8:4/5664:
3 locks held by kworker/0:4/5672:
 #0: ffff888100069d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90004dffc40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff9002dec0 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xac/0x1110
4 locks held by kworker/0:6/5717:
2 locks held by kworker/0:7/9227:
3 locks held by kworker/u8:5/10015:
3 locks held by kworker/u8:7/10017:
3 locks held by kworker/u9:7/14504:
3 locks held by kworker/u8:9/15447:
 #0: ffff8881715cc940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc900057cfc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff9002dec0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
2 locks held by kworker/u8:10/15448:
4 locks held by kworker/u8:11/15450:
3 locks held by kworker/u9:8/19645:
3 locks held by kworker/u9:10/19649:
3 locks held by kworker/u9:11/19652:
3 locks held by kworker/u9:12/19654:
3 locks held by kworker/u9:13/19656:
3 locks held by kworker/u9:14/19658:
3 locks held by kworker/u9:15/19660:
3 locks held by kworker/u9:16/19662:
3 locks held by kworker/u9:19/19667:
3 locks held by kworker/0:10/20560:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc900057efc40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff9002dec0 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
1 lock held by syz-executor/21149:
1 lock held by syz-executor/21371:
3 locks held by kworker/0:11/21427:
1 lock held by syz.9.6382/21990:
4 locks held by kworker/u8:12/22001:
1 lock held by dhcpcd/22006:
 #0: ffff888117c37440 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220
1 lock held by dhcpcd/22007:
 #0: ffff888117c30840 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220
4 locks held by kworker/u8:13/22008:
1 lock held by dhcpcd/22009:
 #0: ffff888117dc1440 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220
1 lock held by dhcpcd/22010:
 #0: ffff888117dc2c40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220
1 lock held by dhcpcd/22011:
 #0: ffff888113780240 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220
2 locks held by dhcpcd/22012:
 #0: ffff888113781440 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220
 #1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz-executor/22015:
2 locks held by syz-executor/22019:
2 locks held by syz-executor/22025:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0x17a/0x380
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
