INFO: task kworker/1:5:5915 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:5 state:D stack:20392 pid:5915 tgid:5915 ppid:2 task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
i2c_del_adapter+0x591/0x760 drivers/i2c/i2c-core-base.c:1814
dvb_usb_i2c_exit+0x64/0xb0 drivers/media/usb/dvb-usb/dvb-usb-i2c.c:46
dvb_usb_exit drivers/media/usb/dvb-usb/dvb-usb-init.c:144 [inline]
dvb_usb_device_exit+0x1be/0x350 drivers/media/usb/dvb-usb/dvb-usb-init.c:338
usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:571 [inline]
__device_release_driver drivers/base/dd.c:1282 [inline]
device_release_driver_internal+0x4d9/0x800 drivers/base/dd.c:1305
bus_remove_device+0x355/0x450 drivers/base/bus.c:616
device_del+0x515/0x8e0 drivers/base/core.c:3878
usb_disable_device+0x3d4/0x8e0 drivers/usb/core/message.c:1418
usb_disconnect+0x315/0x970 drivers/usb/core/hub.c:2345
hub_port_connect drivers/usb/core/hub.c:5407 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1cd9/0x4f30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Showing all locks held in the system:
4 locks held by pr/legacy/17:
4 locks held by rcuc/0/20:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:2/43:
6 locks held by kworker/u8:4/69:
7 locks held by kworker/u8:7/174:
3 locks held by kworker/u8:11/1432:
6 locks held by kworker/u8:12/1454:
1 lock held by klogd/5155:
2 locks held by getty/5555:
#0: ffff8880349f50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
3 locks held by syz-executor/5801:
5 locks held by kworker/1:5/5915:
#0: ffff88801eefcd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88801eefcd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000541fb80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000541fb80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888027bc6188 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888027bc6188 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff8880392b1188 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff8880392b1188 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xde/0x970 drivers/usb/core/hub.c:2336
#4: ffff88805e46c150 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88805e46c150 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline]
#4: ffff88805e46c150 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1302
6 locks held by kworker/0:9/5996:
4 locks held by kworker/u8:21/6618:
4 locks held by kworker/u8:24/6625:
3 locks held by syz.4.2000/12369:
3 locks held by syz.4.2000/12372:
#0: ffff888024bdfa48 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xe10 drivers/block/nbd.c:1656
#1: ffff88814236db38 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:954 [inline]
#1: ffff88814236db38 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: nbd_add_socket+0x312/0xbb0 drivers/block/nbd.c:1262
#2: ffff88814236db70 (&q->q_usage_counter(queue)#37){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:954 [inline]
#2: ffff88814236db70 (&q->q_usage_counter(queue)#37){+.+.}-{0:0}, at: nbd_add_socket+0x312/0xbb0 drivers/block/nbd.c:1262
1 lock held by syz.4.2000/12373:
#0: ffff888024bdfa48 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xe10 drivers/block/nbd.c:1656
4 locks held by syz-executor/12371:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
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:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 9e fa b5 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 7f 61 18 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 8a 3f cc 05 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001678d0 EFLAGS: 00000202
RAX: 1ffffffff31f0700 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff98f83fd0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff850a7750 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff98f83d40 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126d06000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd764cd1d58 CR3: 00000000663b6000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3109 [inline]
console_flush_one_record+0x6b5/0xbe0 kernel/printk/printk.c:3215
legacy_kthread_func+0x16f/0x210 kernel/printk/printk.c:3674
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246