INFO: task syz.4.3333:18471 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3333 state:D stack:27336 pid:18471 tgid:18469 ppid:16973 task_flags:0x40054c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__flush_work+0x7c7/0xcb0 kernel/workqueue.c:4354
__cancel_work_sync kernel/workqueue.c:4474 [inline]
cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4511
hci_cmd_sync_clear+0x33/0x100 net/bluetooth/hci_sync.c:655
hci_unregister_dev+0x1cc/0x670 net/bluetooth/hci_core.c:2712
vhci_release+0x17d/0x230 drivers/bluetooth/hci_vhci.c:690
__fput+0x3ff/0xb50 fs/file_table.c:510
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d2/0x2a60 kernel/exit.c:975
do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
get_signal+0x1ec7/0x21e0 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x8b/0x4f0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7f3c59cdd9
RSP: 002b:00007f7f3d51c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: 0000000000000007 RBX: 00007f7f3c816090 RCX: 00007f7f3c59cdd9
RDX: 0000000000000000 RSI: 0000200000000400 RDI: ffffffffffffff9c
RBP: 00007f7f3c632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7f3c816128 R14: 00007f7f3c816090 R15: 00007ffd5c7092f8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:2/1757:
#0: ffff88813fe5b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc90006227d08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#2: ffffffff8e7f1028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by getty/5361:
#0: ffff888038b370a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:3/16979:
#0: ffff88807a84b140 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc90005557d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#2: ffff88807c4ccea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331
3 locks held by kworker/1:7/19782:
#0: ffff8880206cd540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc9000429fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#2: ffff88802baec1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff88802baec1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
1 lock held by syz.6.3641/20908:
#0: ffffffff8e7f0ef8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
1 lock held by syz.6.3641/20913:
#0: ffffffff8e6aca80 (sched_core_mutex){+.+.}-{4:4}, at: sched_core_get+0x3f/0xa0 kernel/sched/core.c:497
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18442 Comm: kworker/0:10 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: 0x0 (events)
RIP: 0010:__schedule+0x2b5/0x67a0 kernel/sched/core.c:7045
Code: 89 8d d8 fe ff ff 48 c1 ea 03 0f b6 14 02 48 89 c8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 53 51 00 00 41 8b be 28 0c 00 00 <48> 8b b5 70 ff ff ff e8 2f b8 4b f6 31 f6 4c 89 f7 e8 35 2b 4a f6
RSP: 0018:ffffc90004a17c20 EFLAGS: 00000046
RAX: 0000000000000003 RBX: ffffffff8b8bab4d RCX: ffff8880b843be68
RDX: 0000000000000000 RSI: ffffffff8c1c3780 RDI: 0000000000000000
RBP: ffffc90004a17d80 R08: 0000000000000000 R09: fffffbfff21af5aa
R10: ffffffff90d7ad57 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88802ddcaf00 R14: ffff8880b843b240 R15: ffff8880b843a180
FS: 0000000000000000(0000) GS:ffff888124372000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffeb05e9fc0 CR3: 0000000036ed7000 CR4: 00000000003526f0
Call Trace:
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
worker_thread+0x53b/0xe50 kernel/workqueue.c:3481
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245