INFO: task syz.0.843:8921 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.843 state:D stack:25352 pid:8921 tgid:8920 ppid:5825 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5254 [inline]
__schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
__schedule_loop kernel/sched/core.c:6944 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6959
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
comedi_open+0xc0/0x5f0 drivers/comedi/comedi_fops.c:2863
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
do_dentry_open+0x953/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4134
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1e62f8efc9
RSP: 002b:00007f1e63d5c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1e631e5fa0 RCX: 00007f1e62f8efc9
RDX: 0000000000020841 RSI: 0000200000000340 RDI: ffffffffffffff9c
RBP: 00007f1e63011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1e631e6038 R14: 00007f1e631e5fa0 R15: 00007ffe01d56048
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e33d960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33d960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33d960 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:3/37:
#0: ffff88801bedf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
#1: ffffc90000ad7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
#2: ffffffff8f6e08d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:670
#3: ffffffff8f6ede48 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12994
#4: ffffffff8e3433f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#4: ffffffff8e3433f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
6 locks held by kworker/0:3/1219:
#0: ffff888142ad1148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
#1: ffffc90003defba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
#2: ffff8881447b9198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff8881447b9198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
#3: ffff8881447bc518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff8881447bc518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff8881447bc518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff8881447bc518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff8881447bc518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x215a/0x4ef0 drivers/usb/core/hub.c:5953
#4: ffff88814430f868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff88814430f868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff88814430f868 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff88814430f868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2182/0x4ef0 drivers/usb/core/hub.c:5953
#5:
ffff8880b863a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638
2 locks held by getty/5588:
#0: ffff88803520a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/1:4/5921:
#0: ffff888142ad1148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
#1: ffffc90004c1fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
#2: ffff888144759198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888144759198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
#3: ffff88806eafd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88806eafd198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
#4: ffff88807a6cb160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff88807a6cb160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
2 locks held by syz.3.816/8771:
1 lock held by syz.0.843/8921:
#0: ffff88814caaa8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x5f0 drivers/comedi/comedi_fops.c:2863
2 locks held by syz.2.907/9195:
#0: ffff88814caac0f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_unlocked_ioctl+0x146/0x1020 drivers/comedi/comedi_fops.c:2166
#1: ffffffff8f5bab68 (comedi_drivers_list_lock){+.+.}-{4:4}, at: comedi_device_attach+0xc6/0x720 drivers/comedi/drivers.c:970
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:337 [inline]
watchdog+0xfa9/0xff0 kernel/hung_task.c:500
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 11683 Comm: syz.6.1592 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:format_decode+0x530/0xe30 lib/vsprintf.c:2765
Code: 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 f1 05 00 00 41 0f b6 04 24 <4c> 8d 2c 85 c0 a9 b6 8c 44 0f b6 fb 41 c1 e7 08 4c 89 e8 48 c1 e8
RSP: 0018:ffffc90018e37110 EFLAGS: 00000246
RAX: 0000000000000075 RBX: 0000000000000008 RCX: 0000000000000002
RDX: dffffc0000000000 RSI: 0000000000000075 RDI: 000000000000006c
RBP: ffffffff8b8b9403 R08: ffff88802bf79e40 R09: 0000000000000002
R10: 0000000000000025 R11: 0000000000000002 R12: ffffffff8b8b9404
R13: 0000000000000075 R14: 0000000000000000 R15: 0000000000000008
FS: 00007fbda0e026c0(0000) GS:ffff888125b9c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbda0311000 CR3: 0000000032298000 CR4: 00000000003526f0
Call Trace:
vsnprintf+0x102/0xf00 lib/vsprintf.c:2869
sprintf+0xd9/0x120 lib/vsprintf.c:3089
print_time kernel/printk/printk.c:1354 [inline]
info_print_prefix+0x155/0x310 kernel/printk/printk.c:1380
record_print_text+0x154/0x420 kernel/printk/printk.c:1429
printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:2997
console_emit_next_record kernel/printk/printk.c:3062 [inline]
console_flush_one_record kernel/printk/printk.c:3194 [inline]
console_flush_all+0x4cc/0xb10 kernel/printk/printk.c:3268
__console_flush_and_unlock kernel/printk/printk.c:3298 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3338
vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423
_printk+0xcf/0x120 kernel/printk/printk.c:2448
usb_gadget_register_driver_owner+0x20f/0x270 drivers/usb/gadget/udc/core.c:1729
raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:595 [inline]
raw_ioctl+0x1465/0x4050 drivers/usb/gadget/legacy/raw_gadget.c:1304
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd9ff8ebcb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007fbda0dfff10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007fbd9ff8ebcb
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000007
RBP: 00007fbda0e00fe0 R08: 0000000000000000 R09: 00362e6364755f79
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbda0dfffb0 R14: 0000200000000000 R15: 00007fbda0310b88