INFO: task kworker/1:7:6064 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/1:7 state:D stack:22952 pid:6064 tgid:6064 ppid:2 task_flags:0x4208060 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_add_one+0x38/0x840 fs/kernfs/dir.c:791 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1093 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c4/0x9b0 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_add+0x16e/0x240 lib/kobject.c:426 device_add+0x288/0x1a70 drivers/base/core.c:3630 usb_new_device+0xd07/0x1a20 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+0x2fce/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 syz.0.475:6862 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.475 state:D stack:27736 pid:6862 tgid:6862 ppid:2951 task_flags:0x40044c flags:0x00004006 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 sysfs_remove_file include/linux/sysfs.h:777 [inline] driver_remove_file drivers/base/driver.c:201 [inline] driver_remove_file+0x4a/0x60 drivers/base/driver.c:197 remove_bind_files drivers/base/bus.c:605 [inline] bus_remove_driver+0x224/0x2c0 drivers/base/bus.c:743 driver_unregister+0x76/0xb0 drivers/base/driver.c:277 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1732 raw_release+0x1ae/0x2b0 drivers/usb/gadget/legacy/raw_gadget.c:462 __fput+0x402/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86c/0x2bd0 kernel/exit.c:964 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x7c/0xe0 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3e9/0x4b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde7addeb69 RSP: 002b:00007ffd7abbdc88 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffdfc RBX: 000000000004918a RCX: 00007fde7addeb69 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fde7b005fac RBP: 0000000000000bea R08: 00007fde7ac48000 R09: 000000107abbdf7f R10: 00007ffd7abbdd80 R11: 0000000000000246 R12: 00007fde7b005fac R13: 00007ffd7abbdd80 R14: 0000000000049d74 R15: 00007ffd7abbdda0 INFO: task syz.2.479:6873 blocked for more than 144 seconds. Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.479 state:D stack:27736 pid:6873 tgid:6872 ppid:2956 task_flags:0x40044c flags:0x00004006 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 sysfs_remove_file include/linux/sysfs.h:777 [inline] driver_remove_file drivers/base/driver.c:201 [inline] driver_remove_file+0x4a/0x60 drivers/base/driver.c:197 remove_bind_files drivers/base/bus.c:605 [inline] bus_remove_driver+0x224/0x2c0 drivers/base/bus.c:743 driver_unregister+0x76/0xb0 drivers/base/driver.c:277 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1732 raw_release+0x1ae/0x2b0 drivers/usb/gadget/legacy/raw_gadget.c:462 __fput+0x402/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86c/0x2bd0 kernel/exit.c:964 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x7c/0xe0 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3e9/0x4b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd94d9be76b RSP: 002b:00007fd94c024f10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007fd94d9be76b RDX: 00007fd94c025fe0 RSI: 0000000080085502 RDI: 0000000000000003 RBP: 00007fd94c025fe0 R08: 0000000000000080 R09: 00007fd94c024fd8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 0000000000000008 R15: 00007fd94da4d355 Showing all locks held in the system: 4 locks held by kworker/0:0/9: #0: ffff888100080d48 ((wq_completion)events ){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000009fd10 (kernfs_notify_work ){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888100ac4ab8 (&root->kernfs_supers_rwsem ){++++}-{4:4} , at: kernfs_notify_workfn+0xf7/0xb30 fs/kernfs/file.c:914 #3: ffff888100ac4988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_notify_workfn+0xff/0xb30 fs/kernfs/file.c:915 5 locks held by kworker/0:1/10: 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 2 locks held by getty/2904: #0: ffff888109ea50a0 ( &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 1 lock held by syz-executor/2953: #0: ffffffff890d3a38 (rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304 1 lock held by syz-executor/2958: #0: ffffffff890d3a38 ( rcu_state.exp_mutex ){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 1 lock held by udevd/5199: #0: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by udevd/5206: #0: ffff888100ac4988 (&root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 5 locks held by kworker/0:3/5221: 4 locks held by udevd/5241: 1 lock held by udevd/5253: #0: ffff888100ac4988 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 10 locks held by kworker/0:5/5384: 1 lock held by udevd/5590: #0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4} , at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 1 lock held by udevd/5727: #0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180 5 locks held by kworker/0:7/6818: 1 lock held by syz.2.479/6873: 1 lock held by syz-executor/6880: ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6818 Comm: kworker/0:7 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 Workqueue: usb_hub_wq hub_event 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:ffffc900142ef350 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:ffff888269160000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b24955f40 CR3: 00000001193f2000 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_info+0xe4/0x120 drivers/base/core.c:4986 usb_disconnect+0xec/0x9c0 drivers/usb/core/hub.c:2326 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