INFO: task kworker/1:3:17059 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:3 state:D stack:22080 pid:17059 tgid:17059 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 i2c_del_adapter+0x546/0x6f0 drivers/i2c/i2c-core-base.c:1817 dvb_usb_i2c_exit+0x9f/0xf0 drivers/media/usb/dvb-usb/dvb-usb-i2c.c:46 dvb_usb_exit drivers/media/usb/dvb-usb/dvb-usb-init.c:144 [inline] dvb_usb_device_exit+0x334/0x580 drivers/media/usb/dvb-usb/dvb-usb-init.c:338 cxusb_probe+0x1c9/0x7d0 drivers/media/usb/dvb-usb/cxusb.c:1663 usb_probe_interface+0x300/0xa40 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537 device_add+0x1148/0x1aa0 drivers/base/core.c:3689 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250 usb_probe_device+0xef/0x3e0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537 device_add+0x1148/0x1aa0 drivers/base/core.c:3689 usb_new_device+0xd07/0x1a60 drivers/usb/core/hub.c:2694 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2f34/0x4fe0 drivers/usb/core/hub.c:5952 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.4.7566:1605 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.7566 state:D stack:27096 pid:1605 tgid:1604 ppid:26184 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 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+0x81b/0x1060 kernel/locking/mutex.c:760 device_lock include/linux/device.h:911 [inline] usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054 chrdev_open+0x234/0x6a0 fs/char_dev.c:414 do_dentry_open+0x97f/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 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+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6dc418d550 RSP: 002b:00007f6dc5095b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000008041 RCX: 00007f6dc418d550 RDX: 0000000000008041 RSI: 00007f6dc5095c10 RDI: 00000000ffffff9c RBP: 00007f6dc5095c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f6dc43b6038 R14: 00007f6dc43b5fa0 R15: 00007ffc9f4879b8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5609: #0: ffff88803227b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/u9:9/5867: #0: ffff88807784e948 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90003837d10 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff8880592b0dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 5 locks held by kworker/1:3/17059: #0: ffff8880226ac548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9001d3f7d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888144bdd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff888144bdd198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff88805ebd8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff88805ebd8198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff888141bdd160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff888141bdd160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 1 lock held by syz.4.7566/1605: #0: ffff888144bdd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #0: ffff888144bdd198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x8b0 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 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 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: 61 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x43/0xc0 kernel/rcu/tree.c:751 Code: 89 c5 83 f8 07 0f 87 82 00 00 00 48 8d 3c ed 60 ee f5 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c <48> 03 1c ed 60 ee f5 8d 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 RSP: 0018:ffffc9000212f798 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff93d7a2a8 RCX: ffffffff8191dab3 RDX: 1ffffffff1bebdcd RSI: ffffffff8c162880 RDI: ffffffff8df5ee68 RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff2156972 R10: ffffffff90ab4b97 R11: 0000000000000000 R12: 000000000000015e R13: 0000000000000007 R14: 000000000000b7dc R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8881247b9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558ca3e608 CR3: 000000000e380000 CR4: 00000000003526f0 Call Trace: trace_pelt_cfs_tp include/trace/events/sched.h:833 [inline] __update_load_avg_cfs_rq+0x600/0x8f0 kernel/sched/pelt.c:329 update_cfs_rq_load_avg kernel/sched/fair.c:4618 [inline] update_load_avg+0x23f/0x1fc0 kernel/sched/fair.c:4731 dequeue_entity+0x3c0/0x1450 kernel/sched/fair.c:5402 dequeue_entities+0x232/0x15b0 kernel/sched/fair.c:6984 dequeue_task_fair+0x187/0x3b0 kernel/sched/fair.c:7080 block_task kernel/sched/core.c:2155 [inline] try_to_block_task kernel/sched/core.c:6585 [inline] __schedule+0x54a/0x5de0 kernel/sched/core.c:6896 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 toggle_allocation_gate mm/kfence/core.c:852 [inline] toggle_allocation_gate+0x1d9/0x280 mm/kfence/core.c:842 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245