INFO: task kworker/u9:3:2943 blocked for more than 148 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:3    state:D stack:22504 pid:2943  tgid:2943  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7bf/0x1550
 linkwatch_event+0xe/0x60
 process_scheduled_works+0xa8e/0x14e0
 worker_thread+0xa47/0xfb0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task kworker/0:5:6068 blocked for more than 148 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:5     state:D stack:22048 pid:6068  tgid:6068  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7bf/0x1550
 switchdev_deferred_process_work+0xe/0x20
 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/0:1/10:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc900000f7c40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff90027ec0 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x6f/0x770
2 locks held by kworker/u9:0/26:
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/u9:2/1238:
3 locks held by kworker/u9:3/2943:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90021abfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff90027ec0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by kworker/0:2/3158:
3 locks held by kworker/R-ipv6_/3248:
 #0: ffff888177711140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90022bcfc20 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff90027ec0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
1 lock held by klogd/5037:
2 locks held by getty/5426:
 #0: ffff888102aa50a0 (&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
2 locks held by kworker/u8:2/5466:
1 lock held by syz-executor/5527:
5 locks held by kworker/u11:2/5943:
 #0: ffff88803cd9b140 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90006cc7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff8880228a0ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0
 #3: ffff8880228a00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190
 #4: ffffffff901b0000 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x149/0x320
6 locks held by kworker/u11:3/5995:
 #0: ffff888114072140 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90004defc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff888112dacea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0
 #3: ffff888112dac0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190
 #4: ffffffff901b0000 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x149/0x320
 #5: ffff88801287e2f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x9f/0x520
5 locks held by kworker/u8:3/6026:
 #0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90006cb7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff90019328 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810
 #3: ffffffff90027ec0 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x28e/0x8d0
 #4: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
3 locks held by kworker/0:5/6068:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc9000419fc40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff90027ec0 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
3 locks held by kworker/u9:4/6076:
3 locks held by kworker/u9:5/7334:
1 lock held by syz-executor/8638:
2 locks held by kworker/0:6/8703:
2 locks held by kworker/0:8/8705:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90009917c40 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
4 locks held by kworker/u9:9/14587:
3 locks held by kworker/u9:10/14588:
3 locks held by kworker/u9:12/14590:
4 locks held by kworker/u9:14/14592:
6 locks held by kworker/u9:15/14593:
3 locks held by kworker/u9:17/14595:
3 locks held by kworker/u9:19/14600:
3 locks held by kworker/u9:20/14602:
4 locks held by syz-executor/16477:
6 locks held by syz.0.5143/17091:
2 locks held by rm/17636:

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

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>
