INFO: task syz.3.951:9346 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.951 state:D stack:26584 pid:9346 tgid:9345 ppid:5639 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
device_lock include/linux/device.h:1040 [inline]
usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411
do_dentry_open+0x785/0x14e0 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd7c815d60e
RSP: 002b:00007fd7c8fc6b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd7c8fc76c0 RCX: 00007fd7c815d60e
RDX: 0000000000000002 RSI: 00007fd7c8fc6c00 RDI: ffffffffffffff9c
RBP: 00007fd7c8fc6c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007fd7c8416038 R14: 00007fd7c8415fa0 R15: 00007fd7c853fa48
Showing all locks held in the system:
2 locks held by kworker/0:1/10:
5 locks held by kworker/1:0/24:
#0: ffff888021ac6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff888021ac6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc900001e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc900001e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffff8880551bf1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff8880551bf1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff88801e795568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff88801e795568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x631/0x4f30 drivers/usb/core/hub.c:5952
#4: ffff888029293090 (&hub->status_mutex){+.+.}-{4:4}, at: hub_ext_port_status+0x53/0x820 drivers/usb/core/hub.c:623
6 locks held by kworker/1:1/29:
1 lock held by khungtaskd/31:
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5381:
#0: ffff888031e1e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:4/5619:
#0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc90003d07c40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc90003d07c40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
3 locks held by kworker/0:5/5681:
#0: ffff888021ac6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff888021ac6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc90004117c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc90004117c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffff88802a24c1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff88802a24c1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
8 locks held by kworker/0:6/5682:
5 locks held by kworker/1:4/5690:
#0: ffff888021ac6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff888021ac6540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1:
ffffc900041a7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
ffffc900041a7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffff88802a49b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff88802a49b1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff88807ddd91d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#3: ffff88807ddd91d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
#4: ffff88807a00b1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff88807a00b1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
4 locks held by udevd/9064:
#0: ffff8880634eeab8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183
#1: ffff8880335b1c80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff888033a01e18 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888033a01e18 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff88807ddd91d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline]
#3: ffff88807ddd91d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz.3.951/9346:
#0: ffff88802a47b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#0: ffff88802a47b1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
1 lock held by syz.4.1097/9926:
#0: ffff88802a47b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#0: ffff88802a47b1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
1 lock held by syz.6.1473/11313:
#0: ffffffff8e962f38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
2 locks held by dhcpcd/11351:
#0: ffff888032f08260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
#0: ffff888032f08260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204
#1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 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_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 5690 Comm: kworker/1:4 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: usb_hub_wq hub_event
RIP: 0010:format_decode+0x52b/0xe10 lib/vsprintf.c:2786
Code: 21 f6 49 89 ec 49 ff c4 4c 89 e0 48 c1 e8 03 48 ba 00 00 00 00 00 fc ff df 0f b6 04 10 84 c0 4c 8b 74 24 18 0f 85 cd 05 00 00 <41> 0f b6 04 24 4c 8d 2c 85 60 b4 0b 8d 44 0f b6 fb 41 c1 e7 08 4c
RSP: 0018:ffffc900041a60d0 EFLAGS: 00000293
RAX: 0000000000000005 RBX: 0000000000000008 RCX: 000000008bcd8302
RDX: dffffc0000000000 RSI: 0000000000000075 RDI: 000000000000006c
RBP: ffffffff8bcd83e9 R08: ffff88807706dc40 R09: 0000000000000002
R10: 0000000000000025 R11: 0000000000000002 R12: ffffffff8bcd83ea
R13: 0000000000000075 R14: 0000000000000800 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff888125393000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000749a6000 CR4: 00000000003526f0
Call Trace:
vsnprintf+0x102/0xee0 lib/vsprintf.c:2890
sprintf+0xe7/0x140 lib/vsprintf.c:3111
print_time kernel/printk/printk.c:1359 [inline]
info_print_prefix+0x16b/0x360 kernel/printk/printk.c:1385
record_print_text+0x176/0x450 kernel/printk/printk.c:1434
printk_get_next_message+0x29c/0x880 kernel/printk/printk.c:3072
console_emit_next_record kernel/printk/printk.c:3137 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x501/0xb20 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
dvb_usb_download_firmware+0xf2/0x270 drivers/media/usb/dvb-usb/dvb-usb-firmware.c:99
dvb_usb_device_init+0xde2/0x2590 drivers/media/usb/dvb-usb/dvb-usb-init.c:298
dib0700_probe+0xea/0x310 drivers/media/usb/dvb-usb/dib0700_core.c:883
usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:709
__driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
__device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c5/0x450 drivers/base/dd.c:1101
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
device_add+0x7e9/0xbb0 drivers/base/core.c:3706
usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2268
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:709
__driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
__device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c5/0x450 drivers/base/dd.c:1101
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
device_add+0x7e9/0xbb0 drivers/base/core.c:3706
usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245