INFO: task kworker/1:2:922 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:25576 pid:922 tgid:922 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 schedule_timeout+0xc0/0x2c0 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+0x2ca/0x5e0 kernel/sched/completion.c:153 i2c_del_adapter+0x292/0x440 drivers/i2c/i2c-core-base.c:1847 i2c_tiny_usb_disconnect+0x49/0xd0 drivers/i2c/busses/i2c-tiny-usb.c:282 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:618 [inline] __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372 bus_remove_device+0x444/0x560 drivers/base/bus.c:664 device_del+0x524/0x8f0 drivers/base/core.c:3965 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2350 hub_port_connect drivers/usb/core/hub.c:5420 [inline] hub_port_connect_change drivers/usb/core/hub.c:5720 [inline] port_event drivers/usb/core/hub.c:5884 [inline] hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5966 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 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 INFO: task syz-executor366:5632 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor366 state:D stack:26472 pid:5632 tgid:5632 ppid:5630 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 device_lock include/linux/device.h:1104 [inline] usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054 chrdev_open+0x4d9/0x600 fs/char_dev.c:411 do_dentry_open+0x816/0x1380 fs/open.c:996 vfs_open+0x3b/0x340 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x1443/0x1d60 fs/namei.c:5000 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f129701f397 RSP: 002b:00007ffe3a00a460 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055556832f400 RCX: 00007f129701f397 RDX: 0000000000188301 RSI: 00007ffe3a00a520 RDI: ffffffffffffff9c RBP: 00007ffe3a00a520 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: cccccccccccccccd R13: 0000000000000002 R14: 00007ffe3a00a960 R15: 00007ffe3a00a950 INFO: task syz-executor366:5634 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor366 state:D stack:26400 pid:5634 tgid:5634 ppid:5631 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 device_lock include/linux/device.h:1104 [inline] usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054 chrdev_open+0x4d9/0x600 fs/char_dev.c:411 do_dentry_open+0x816/0x1380 fs/open.c:996 vfs_open+0x3b/0x340 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x1443/0x1d60 fs/namei.c:5000 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f129701f397 RSP: 002b:00007ffe3a00a460 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055556832f400 RCX: 00007f129701f397 RDX: 0000000000188301 RSI: 00007ffe3a00a520 RDI: ffffffffffffff9c RBP: 00007ffe3a00a520 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: cccccccccccccccd R13: 0000000000000002 R14: 00007ffe3a00a960 R15: 00007ffe3a00a950 INFO: task syz-executor366:5636 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor366 state:D stack:26088 pid:5636 tgid:5636 ppid:5633 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 device_lock include/linux/device.h:1104 [inline] usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054 chrdev_open+0x4d9/0x600 fs/char_dev.c:411 do_dentry_open+0x816/0x1380 fs/open.c:996 vfs_open+0x3b/0x340 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x1443/0x1d60 fs/namei.c:5000 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f129701f397 RSP: 002b:00007ffe3a00a460 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055556832f400 RCX: 00007f129701f397 RDX: 0000000000188301 RSI: 00007ffe3a00a520 RDI: ffffffffffffff9c RBP: 00007ffe3a00a520 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: cccccccccccccccd R13: 0000000000000002 R14: 00007ffe3a00a960 R15: 00007ffe3a00a950 INFO: task syz-executor366:5638 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor366 state:D stack:26760 pid:5638 tgid:5638 ppid:5635 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7426 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 device_lock include/linux/device.h:1104 [inline] usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054 chrdev_open+0x4d9/0x600 fs/char_dev.c:411 do_dentry_open+0x816/0x1380 fs/open.c:996 vfs_open+0x3b/0x340 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x1443/0x1d60 fs/namei.c:5000 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f129701f397 RSP: 002b:00007ffe3a00a460 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055556832f400 RCX: 00007f129701f397 RDX: 0000000000188301 RSI: 00007ffe3a00a520 RDI: ffffffffffffff9c RBP: 00007ffe3a00a520 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: cccccccccccccccd R13: 0000000000000002 R14: 00007ffe3a00a960 R15: 00007ffe3a00a950 Showing all locks held in the system: locks held by khungtaskd/32: 1, last CPU#1: #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c8e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:3/50: 2, on CPU#1: #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90000bb7c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90000bb7c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90000bb7c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90000bb7c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 locks held by kworker/1:2/922: 5, on CPU#1: #0: ffff8880222e0d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff8880222e0d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff8880222e0d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff8880222e0d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90004a07c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90004a07c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90004a07c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90004a07c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912 #3: ffff888021ec61d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff888021ec61d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0 drivers/usb/core/hub.c:2341 #4: ffff8880226a81a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff8880226a81a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff8880226a81a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 locks held by getty/5371: 2, on CPU#1: #0: ffff8880363330a0 (&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+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor366/5632: 1, on CPU#0: #0: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #0: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054 locks held by syz-executor366/5634: 1, on CPU#0: #0: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #0: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054 locks held by syz-executor366/5636: 1, on CPU#0: #0: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #0: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054 locks held by syz-executor366/5638: 1, on CPU#0: #0: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #0: ffff888029d1a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x480 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 1c 89 02 c3 cc cc cc cc 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 31 24 00 fb f4 8c 08 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8ea07ca0 EFLAGS: 00000242 RAX: 00000000001f2d75 RBX: ffffffff819bb370 RCX: 8000000000000001 RDX: 0000000000000001 RSI: ffffffff8e41399c RDI: ffffffff8c6da080 RBP: ffffffff8ea07d78 R08: ffff8880b8633a1b R09: 1ffff110170c6743 R10: dffffc0000000000 R11: ffffed10170c6744 R12: 0000000000000000 R13: 1ffffffff1d51e00 R14: 1ffffffff1d40f9c R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888124cd1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055bb4b463f20 CR3: 00000000254e2000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x2e0/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 rest_init+0x378/0x3a0 init/main.c:732 start_kernel+0x392/0x3e0 init/main.c:1190 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x157