INFO: task kworker/0:0:9 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:0 state:D stack:23112 pid:9 tgid:9 ppid:2 task_flags:0x4288060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x1325/0x3b10 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_write_slowpath+0x524/0x1310 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1d6/0x200 kernel/locking/rwsem.c:1578 kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] sysfs_unmerge_group+0xe7/0x170 fs/sysfs/group.c:402 dev_pm_qos_constraints_destroy+0x30/0x780 drivers/base/power/qos.c:260 dpm_sysfs_remove+0x70/0xb0 drivers/base/power/sysfs.c:831 device_del+0x1a0/0x9f0 drivers/base/core.c:3856 device_unregister+0x1d/0xc0 drivers/base/core.c:3922 usb_remove_ep_devs+0x42/0x80 drivers/usb/core/endpoint.c:189 remove_intf_ep_devs drivers/usb/core/message.c:1266 [inline] usb_disable_device+0x309/0x7d0 drivers/usb/core/message.c:1417 usb_disconnect+0x2e1/0x9c0 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+0x1aa2/0x5060 drivers/usb/core/hub.c:5952 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task jbd2/sda1-8:2804 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:26392 pid:2804 tgid:2804 ppid:2 task_flags:0x240040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x1325/0x3b10 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 io_schedule+0xbf/0x130 kernel/sched/core.c:7724 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] __wait_on_buffer+0x64/0x70 fs/buffer.c:123 wait_on_buffer include/linux/buffer_head.h:422 [inline] journal_wait_on_commit_record fs/jbd2/commit.c:171 [inline] jbd2_journal_commit_transaction+0x4a88/0x68f0 fs/jbd2/commit.c:881 kjournald2+0x1f4/0x760 fs/jbd2/journal.c:201 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 6 locks held by kworker/0:0/9: #0: ffff8881066f3148 ( (wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000009fd10 ( (work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810b71f198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff888116c4d198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2335 #4: ffffffff897bdb68 ( dev_pm_qos_sysfs_mtx ){+.+.}-{4:4} , at: dev_pm_qos_constraints_destroy+0x28/0x780 drivers/base/power/qos.c:254 #5: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712 5 locks held by ksoftirqd/1/22: 5 locks held by kworker/1:0/23: #0: ffff8881066f3148 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000018fd10 ( (work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810b737198 ( &dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff88811be67198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #4: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_activate fs/kernfs/dir.c:1425 [inline] , at: kernfs_add_one+0x349/0x840 fs/kernfs/dir.c:834 1 lock held by khungtaskd/30: #0: ffffffff890c8440 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] , at: rcu_read_lock include/linux/rcupdate.h:841 [inline] , at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 5 locks held by kworker/1:1/37: 1 lock held by udevd/2843: #0: ffff888100ac4988 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 2 locks held by getty/2907: #0: ffff8881123620a0 ( &tty->ldisc_sem ){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 ( &ldata->atomic_read_lock){+.+.}-{4:4} , at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 8 locks held by kworker/1:2/2937: #0: ffff8881066f3148 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000557d10 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88810b7cf198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff88811bc35198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #4: ffff88811c07f160 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:884 [inline] , at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #5: ffffffff89c1b1b0 (minor_rwsem ){+.+.}-{4:4} , at: usb_register_dev+0x11d/0x560 drivers/usb/core/file.c:134 #6: ffffffff897a7168 ( gdp_mutex ){+.+.}-{4:4} , at: get_device_parent+0x10a/0x4e0 drivers/base/core.c:3269 #7: ffff888100ac4988 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791 4 locks held by udevd/2970: #0: ffff8881195800a0 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff88811b6eb088 ( &of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888112c6a968 ( kn->active#19 ){.+.+}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811bc50198 ( &dev->mutex ){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:889 [inline] , at: product_show+0x26/0xa0 drivers/usb/core/sysfs.c:141 1 lock held by udevd/2971: #0: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 3 locks held by kworker/1:3/2972: 2 locks held by udevd/2974: #0: ffff8881270c5a28 ( &type->i_mutex_dir_key #4){++++}-{4:4} , at: inode_lock_shared include/linux/fs.h:884 [inline] , at: open_last_lookups fs/namei.c:3815 [inline] , at: path_openat+0x818/0x2cb0 fs/namei.c:4052 #1: ffff888100ac4988 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_iop_lookup+0x5b/0x2d0 fs/kernfs/dir.c:1222 1 lock held by udevd/2978: #0: ffffffff890d3a38 ( rcu_state.exp_mutex ){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304 1 lock held by udevd/3000: #0: ffff888100ac4988 ( &root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by udevd/3004: #0: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162 4 locks held by udevd/3005: #0: ffff88811bd7e8b8 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff888119f27888 ( &of->mutex#2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888113de7698 ( kn->active #18){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811be67198 ( &dev->mutex ){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:889 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/3007: #0: ffff88811bd98540 ( &p->lock){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff88811bff9888 ( &of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff8881138c4d28 ( kn->active#18 ){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811bc35198 ( &dev->mutex ){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:889 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/3012: #0: ffff88811bd982f0 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff88811bff9088 ( &of->mutex#2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff8881138c4d28 ( kn->active #18){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811bc35198 ( &dev->mutex ){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:889 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary) 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 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: imon 3-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 22 Comm: ksoftirqd/1 Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:416 Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d e9 46 87 5c 04 e8 c1 1e 05 ff eb a0 e8 4a 1f 05 RSP: 0018:ffffc9000017f320 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff82d57865 RDI: ffffffff9392af80 RBP: ffffffff9392af40 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff9392af40 R15: ffffffff9392b200 FS: 0000000000000000(0000) GS:ffff888269260000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005609fa9bf000 CR3: 0000000128c04000 CR4: 00000000003506f0 Call Trace: serial_out drivers/tty/serial/8250/8250.h:142 [inline] serial8250_clear_IER+0x9b/0xc0 drivers/tty/serial/8250/8250_port.c:713 serial8250_console_write+0x255/0x1890 drivers/tty/serial/8250/8250_port.c:3421 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x801/0xc60 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3325 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450 dev_vprintk_emit drivers/base/core.c:4917 [inline] dev_printk_emit+0xfa/0x140 drivers/base/core.c:4928 __dev_printk+0xf5/0x270 drivers/base/core.c:4940 _dev_warn+0xe4/0x120 drivers/base/core.c:4984 usb_rx_callback_intf0+0x11c/0x1a0 drivers/media/rc/imon.c:1768 __usb_hcd_giveback_urb+0x38d/0x6e0 drivers/usb/core/hcd.c:1663 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1747 dummy_timer+0x1814/0x3a30 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842 handle_softirqs+0x208/0x8d0 kernel/softirq.c:579 run_ksoftirqd kernel/softirq.c:968 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960 smpboot_thread_fn+0x3f4/0xae0 kernel/smpboot.c:164 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.159 msecs