INFO: task syz-executor:6112 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00281-gf4a40a4282f4 #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21960 pid:6112  tgid:6112  ppid:1      task_flags:0x40054c flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148
 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4246
 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4366
 hci_cmd_sync_clear+0x30/0x230 net/bluetooth/hci_sync.c:655
 hci_unregister_dev+0x194/0x510 net/bluetooth/hci_core.c:2713
 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x44c/0xa70 fs/file_table.c:465
 task_work_run+0x1d1/0x260 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x6b5/0x22e0 kernel/exit.c:964
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb637d8d3bc
RSP: 002b:00007ffdeaa72eb0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fb637d8d3bc
RDX: 0000000000000030 RSI: 00007ffdeaa72f70 RDI: 00000000000000f9
RBP: 00007ffdeaa72f1c R08: 0000000000000000 R09: 0079746972756365
R10: 00007ffdeaa72870 R11: 0000000000000246 R12: 0000000000000258
R13: 00000000000927c0 R14: 000000000004af9d R15: 00007ffdeaa72f70
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by kworker/u4:2/31:
3 locks held by kworker/u5:0/45:
 #0: ffff88801a250148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a250148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc90000607bc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000607bc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffff8880440b8dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0 net/bluetooth/hci_sync.c:331
2 locks held by getty/5126:
 #0: ffff888000cc90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/12720:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller-00281-gf4a40a4282f4 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>