INFO: task kworker/1:5:5914 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:20232 pid:5914 tgid:5914 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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:1814 cp2112_remove+0x5b/0x100 drivers/hid/hid-cp2112.c:1345 hid_device_remove+0x225/0x370 drivers/hid/hid-core.c:-1 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1274 [inline] device_release_driver_internal+0x46c/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 hid_remove_device drivers/hid/hid-core.c:3008 [inline] hid_destroy_device+0x6b/0x1b0 drivers/hid/hid-core.c:3030 usbhid_disconnect+0x9f/0xc0 drivers/hid/usbhid/hid-core.c:1462 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_port_connect drivers/usb/core/hub.c:5406 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x1cf5/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 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 INFO: task syz.7.1699:13032 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.1699 state:D stack:24648 pid:13032 tgid:13031 ppid:8858 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 device_lock include/linux/device.h:914 [inline] usbdev_release+0x7e/0x760 drivers/usb/core/devio.c:1099 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd4d0d8eec9 RSP: 002b:00007fd4d1bbe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 00007fd4d0fe5fa0 RCX: 00007fd4d0d8eec9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000009 RBP: 00007fd4d0e11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd4d0fe6038 R14: 00007fd4d0fe5fa0 R15: 00007fd4d110fa28 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5587: #0: ffff88814d3140a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 6 locks held by kworker/1:5/5914: #0: ffff88801e2a4d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801e2a4d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900045ffba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900045ffba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff8880332a1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff8880332a1198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950 drivers/usb/core/hub.c:2335 #4: ffff88807c66c160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff88807c66c160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff88807c66c160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 #5: ffff888078401a20 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #5: ffff888078401a20 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #5: ffff888078401a20 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 1 lock held by syz.7.1699/13032: #0: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: usbdev_release+0x7e/0x760 drivers/usb/core/devio.c:1099 1 lock held by syz.5.1806/13513: #0: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054 1 lock held by syz.9.1891/13968: #0: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054 1 lock held by syz.8.1940/14160: #0: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff888144bfe198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054 1 lock held by syz.1.2215/15550: #0: ffffffff8e142c80 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820 ============================================= 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:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 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: 10303 Comm: kworker/u8:48 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:unwind_next_frame+0x116b/0x2390 arch/x86/kernel/unwind_orc.c:-1 Code: 4c 89 ef e8 e7 14 b2 00 48 8b 14 24 4d 89 65 00 41 0f b6 04 2f 84 c0 0f 85 f9 0f 00 00 c6 03 00 4c 8b 64 24 10 4c 8b 7c 24 28 <48> 8b 44 24 40 0f b6 04 28 84 c0 0f 85 8a 0d 00 00 41 0f b6 04 2f RSP: 0018:ffffc9000bb1f438 EFLAGS: 00000246 RAX: ffffc9000bb1f5b8 RBX: ffffc9000bb1f5a0 RCX: 0000000000000000 RDX: ffffffff902b5d44 RSI: 0000000000000000 RDI: ffffc9000bb1f5c8 RBP: dffffc0000000000 R08: ffffc9000bb1f5c7 R09: 0000000000000000 R10: ffffc9000bb1f5b8 R11: fffff52001763eb9 R12: ffffc9000bb1f600 R13: ffffc9000bb1f5b8 R14: ffffc9000bb1f568 R15: 1ffffffff2056ba8 FS: 0000000000000000(0000) GS:ffff888125e0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fccbddb4198 CR3: 00000000725f6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000006800 DR2: 0000000000009951 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2515 [inline] slab_free mm/slub.c:6574 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6684 nsim_dev_trap_report drivers/net/netdevsim/dev.c:836 [inline] nsim_dev_trap_report_work+0x7cf/0xb80 drivers/net/netdevsim/dev.c:866 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 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