INFO: task kworker/1:0:19 blocked for more than 140 seconds.
      Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:0     D25888    19      2 0x80000000
Workqueue: events linkwatch_event
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
 __mutex_lock_common kernel/locking/mutex.c:1016 [inline]
 __mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078
 linkwatch_event+0xb/0x60 net/core/link_watch.c:236
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Showing all locks held in the system:
Bluetooth: hci1: command 0x041b tx timeout
1 lock held by systemd/1:
2 locks held by kworker/0:0/5:
3 locks held by kworker/1:0/19:
Bluetooth: hci2: command 0x0409 tx timeout
Bluetooth: hci0: command 0x0419 tx timeout
 #0: 00000000cc8f537b ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
Bluetooth: hci3: command 0x041b tx timeout
 #1: 00000000f2854f08 ((linkwatch_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
Bluetooth: hci6: command 0x041b tx timeout
 #2: 000000003a10df05 (rtnl_mutex){+.+.}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:236
2 locks held by kworker/u4:1/23:
3 locks held by kworker/1:1/52:
 #0: 00000000cc8f537b ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124