INFO: task syz.4.4067:12097 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.4067      state:D stack:20584 pid:12097 tgid:12091 ppid:8726   task_flags:0x480140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 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+0x581/0x6e0 drivers/i2c/i2c-core-base.c:1817
 em28xx_i2c_unregister+0x4b/0x60 drivers/media/usb/em28xx/em28xx-i2c.c:1027
 em28xx_release_resources+0x14c/0x240 drivers/media/usb/em28xx/em28xx-cards.c:3536
 em28xx_usb_disconnect+0x19f/0x2f0 drivers/media/usb/em28xx/em28xx-cards.c:4201
 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:1274 [inline]
 device_release_driver_internal+0x4d6/0x800 drivers/base/dd.c:1297
 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579
 device_del+0x511/0x8e0 drivers/base/core.c:3878
 usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1418
 usb_disconnect+0x330/0x950 drivers/usb/core/hub.c:2344
 hub_quiesce+0x171/0x330 drivers/usb/core/hub.c:1409
 hub_disconnect+0xc8/0x470 drivers/usb/core/hub.c:1815
 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:1274 [inline]
 device_release_driver_internal+0x4d6/0x800 drivers/base/dd.c:1297
 proc_ioctl+0x290/0x690 drivers/usb/core/devio.c:2360
 proc_ioctl_default+0xbc/0x100 drivers/usb/core/devio.c:2403
 usbdev_do_ioctl drivers/usb/core/devio.c:2767 [inline]
 usbdev_ioctl+0x1376/0x20c0 drivers/usb/core/devio.c:2827
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f642978eec9
RSP: 002b:00007f642a612038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f64299e6180 RCX: 00007f642978eec9
RDX: 0000200000000200 RSI: 00000000c0105512 RDI: 000000000000000d
RBP: 00007f6429811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f64299e6218 R14: 00007f64299e6180 R15: 00007f6429b0fa28
 </TASK>
INFO: task syz.4.4067:12100 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.4067      state:D stack:28936 pid:12100 tgid:12091 ppid:8726   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 device_lock include/linux/device.h:911 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
 usbdev_ioctl+0x140/0x20c0 drivers/usb/core/devio.c:2827
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f642978eec9
RSP: 002b:00007f642a5f1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f64299e6270 RCX: 00007f642978eec9
RDX: 0000200000000000 RSI: 00000000c0105512 RDI: 000000000000000d
RBP: 00007f6429811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f64299e6308 R14: 00007f64299e6270 R15: 00007f6429b0fa28
 </TASK>
INFO: task syz.0.4086:12247 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.4086      state:D stack:23176 pid:12247 tgid:12239 ppid:5627   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 device_lock include/linux/device.h:911 [inline]
 usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414
 do_dentry_open+0x950/0x13f0 fs/open.c:965
 vfs_open+0x3b/0x340 fs/open.c:1095
 do_open fs/namei.c:3887 [inline]
 path_openat+0x2ee5/0x3830 fs/namei.c:4046
 do_filp_open+0x1fa/0x410 fs/namei.c:4073
 do_sys_openat2+0x121/0x1c0 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_openat fs/open.c:1466 [inline]
 __se_sys_openat fs/open.c:1461 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1461
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f403a78d710
RSP: 002b:00007f403b5e7b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000041341 RCX: 00007f403a78d710
RDX: 0000000000041341 RSI: 00007f403b5e7c10 RDI: 00000000ffffff9c
RBP: 00007f403b5e7c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f403a9e6308 R14: 00007f403a9e6270 R15: 00007f403ab0fa28
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5626:
 #0: ffff88803440f0a0 (&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 syz.4.4067/12097:
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: usbdev_ioctl+0x140/0x20c0 drivers/usb/core/devio.c:2827
 #1: ffff888028a59160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #1: ffff888028a59160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
 #1: ffff888028a59160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
 #2: ffff888021796198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #2: ffff888021796198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950 drivers/usb/core/hub.c:2335
 #3: ffff888033865160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #3: ffff888033865160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
 #3: ffff888033865160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
 #4: ffff888068a95ba8 (&dev->lock#4){+.+.}-{4:4}, at: em28xx_release_resources+0x75/0x240 drivers/media/usb/em28xx/em28xx-cards.c:3530
1 lock held by syz.4.4067/12100:
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: usbdev_ioctl+0x140/0x20c0 drivers/usb/core/devio.c:2827
1 lock held by syz.0.4086/12247:
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.5.4260/15093:
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.3.4572/18389:
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #0: ffff888028a58198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054

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

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 08/18/2025
Call Trace:
 <TASK>
 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:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d b3 b9 0d 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: 334b0b1499b4e900 RBX: ffffffff81968528 RCX: 334b0b1499b4e900
RDX: 0000000000000001 RSI: ffffffff8d9ba4bd RDI: ffffffff8be33f80
RBP: ffffc90000197f20 R08: ffff8880b8732f9b R09: 1ffff110170e65f3
R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fa3a830
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a58b40
FS:  0000000000000000(0000) GS:ffff888125d12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff30850eccc CR3: 000000005d63e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>