INFO: task syz.6.4730:27976 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.4730      state:D stack:26376 pid:27976 ppid:19975  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
 device_lock include/linux/device.h:995 [inline]
 usbdev_open+0x183/0x770 drivers/usb/core/devio.c:1051
 chrdev_open+0x5cc/0x6a0 fs/char_dev.c:414
 do_dentry_open+0x8c6/0x1500 fs/open.c:929
 do_open fs/namei.c:3640 [inline]
 path_openat+0x27f1/0x3230 fs/namei.c:3797
 do_filp_open+0x1f5/0x430 fs/namei.c:3824
 do_sys_openat2+0x134/0x1d0 fs/open.c:1421
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff10755cfce
RSP: 002b:00007ff108410b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff1084116c0 RCX: 00007ff10755cfce
RDX: 0000000000048b01 RSI: 00007ff108410c00 RDI: ffffffffffffff9c
RBP: 00007ff108410c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007ff107816038 R14: 00007ff107815fa0 R15: 00007ffc89c85b18
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
5 locks held by kworker/1:2/788:
1 lock held by klogd/5128:
2 locks held by getty/5524:
 #0: ffff88802c9f80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
1 lock held by syz.6.4730/27976:
 #0: ffff888143778190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
 #0: ffff888143778190 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x183/0x770 drivers/usb/core/devio.c:1051

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf3d/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 788 Comm: kworker/1:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x60 kernel/kcov.c:219
Code: 8b 15 51 99 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 <48> 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39
RSP: 0018:ffffc90003b866d0 EFLAGS: 00000246
RAX: ffffffff813b3c99 RBX: ffffffff8f11af08 RCX: ffff888021168000
RDX: 0000000000000002 RSI: ffffffff8cfa0740 RDI: 0000000000000002
RBP: ffffc90003b867f8 R08: ffff888021168000 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000002 R12: ffffc90003b867a8
R13: dffffc0000000000 R14: 0000000000000002 R15: ffffffff8f11af0d
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056148b3c5660 CR3: 000000002b3e6000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 unwind_next_frame+0x679/0x2970 arch/x86/kernel/unwind_orc.c:505
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kmalloc include/linux/slab.h:600 [inline]
 dummy_urb_enqueue+0x7c/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1272
 usb_hcd_submit_urb+0x313/0x1a80 drivers/usb/core/hcd.c:1535
 ath6kl_usb_post_recv_transfers+0x3cd/0x6f0 drivers/net/wireless/ath/ath6kl/usb.c:450
 ath6kl_usb_start_recv_pipes drivers/net/wireless/ath/ath6kl/usb.c:498 [inline]
 hif_start drivers/net/wireless/ath/ath6kl/usb.c:703 [inline]
 ath6kl_usb_power_on+0x6a/0x280 drivers/net/wireless/ath/ath6kl/usb.c:1062
 ath6kl_hif_power_on drivers/net/wireless/ath/ath6kl/hif-ops.h:136 [inline]
 ath6kl_core_init+0x1da/0x1090 drivers/net/wireless/ath/ath6kl/core.c:97
 ath6kl_usb_probe+0x14be/0x15b0 drivers/net/wireless/ath/ath6kl/usb.c:1168
 usb_probe_interface+0x5c9/0xb20 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x25b/0xb20 drivers/base/dd.c:658
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
 __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
 bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
 __device_attach+0x2c2/0x420 drivers/base/dd.c:1030
 bus_probe_device+0x180/0x260 drivers/base/bus.c:534
 device_add+0x85b/0xc20 drivers/base/core.c:3683
 usb_set_configuration+0x1a79/0x20c0 drivers/usb/core/message.c:2207
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:238
 usb_probe_device+0x13d/0x270 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x25b/0xb20 drivers/base/dd.c:658
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
 __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
 bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
 __device_attach+0x2c2/0x420 drivers/base/dd.c:1030
 bus_probe_device+0x180/0x260 drivers/base/bus.c:534
 device_add+0x85b/0xc20 drivers/base/core.c:3683
 usb_new_device+0xa3c/0x1660 drivers/usb/core/hub.c:2660
 hub_port_connect drivers/usb/core/hub.c:5529 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
 port_event drivers/usb/core/hub.c:5833 [inline]
 hub_event+0x29bf/0x49f0 drivers/usb/core/hub.c:5915
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>