INFO: task kworker/1:0:23 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0 state:D
stack:21592 pid:23 tgid:23 ppid:2 task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xeb1/0x4220 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
rwsem_down_write_slowpath+0x530/0x1280 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1591
kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717
bus_remove_device+0x2bc/0x560 drivers/base/bus.c:657
device_del+0x376/0x9b0 drivers/base/core.c:3880
INFO: task kworker/1:2:783 blocked for more than 174 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2 state:D stack:22104 pid:783 tgid:783 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events request_firmware_work_func
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xeb1/0x4220 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
device_lock include/linux/device.h:949 [inline]
ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline]
ath9k_hif_usb_firmware_cb+0x3b5/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294
request_firmware_work_func+0x13c/0x250 drivers/base/firmware_loader/main.c:1152
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
#0: ffff8881000ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1:
ffffc900000cfd18
(
connector_reaper_work
){+.+.}-{0:0}
, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
5 locks held by kworker/1:0/23:
5 locks held by kworker/1:1/28:
#0: ffff888102ac1d48
(
(wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc900001e7d18
((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffff88810b3d31e0
(&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
(&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88810b3d0558 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff88810b3d0558 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff88810b3d0558 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff88810b3d0558 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff88810b3d0558 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953
#4: ffff88810a7cb468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff88810a7cb468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff88810a7cb468 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff88810a7cb468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953
1 lock held by khungtaskd/30:
#0:
ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:8/352:
#0:
ffff888101299148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc90001be7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffffffff8aae3870 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x9e0 net/core/net_namespace.c:675
2 locks held by kworker/u8:15/1511:
#0: ffff8881000ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc900039bfd18 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
5 locks held by kworker/0:2/2821:
2 locks held by getty/2925:
#0: ffff88811636b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:4/5231:
4 locks held by kworker/1:7/5954:
#0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc90012f8fd18 (kernfs_notify_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffff8881012982b8 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_notify_workfn+0xf7/0x5f0 fs/kernfs/file.c:932
#3: ffff888101298188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_notify_workfn+0xff/0x5f0 fs/kernfs/file.c:933
1 lock held by syz.2.273/6247:
#0: ffffffff896ea2b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.3.274/6253:
#0: ffffffff896ea2b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by kworker/u8:1/6265:
#0: ffff8881000ac948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc90013657d18 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
2 locks held by kworker/u8:2/6266:
#0: ffff8881000ac948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc90000567d18 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
1 lock held by modprobe/6272:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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:161 [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:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 23 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:408
Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d c3 cc cc cc cc e8 e1 78 f5 fe eb a0 e8 6a 79 f5
RSP: 0018:ffffc9000018ee60 EFLAGS: 00000002
RAX: 000000000000002e RBX: 00000000000003f8 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: ffffffff83208635 RDI: ffffffff941b8be0
RBP: ffffffff941b8ba0 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 000000000000002e R14: 0000000000000010 R15: ffffffff832085d0
FS: 0000000000000000(0000) GS:ffff8882687c9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f24a4692a90 CR3: 00000001346d8000 CR4: 00000000003506f0
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3217 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3279 [inline]
serial8250_console_write+0xde8/0x1900 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record+0x790/0xe50 kernel/printk/printk.c:3269
console_flush_all kernel/printk/printk.c:3343 [inline]
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0x103/0x260 kernel/printk/printk.c:3413
vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479