INFO: task kworker/0:3:5228 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:3 state:D stack:20392 pid:5228 tgid:5228 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145d/0x4a00 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] kobject_uevent_env+0xb88/0x1920 lib/kobject_uevent.c:608 device_add+0x1103/0x1980 drivers/base/core.c:3670 usb_new_device+0xd07/0x1a90 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x31bf/0x5420 drivers/usb/core/hub.c:5953 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task syz.2.349:6417 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.349 state:D stack:27768 pid:6417 tgid:6417 ppid:2975 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145d/0x4a00 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] kobject_uevent_env+0xb88/0x1920 lib/kobject_uevent.c:608 device_remove+0xcb/0x170 drivers/base/dd.c:569 __device_release_driver drivers/base/dd.c:1282 [inline] device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1305 driver_detach+0xd8/0x1b0 drivers/base/dd.c:1368 bus_remove_driver+0x13b/0x2e0 drivers/base/bus.c:784 driver_unregister+0x76/0xb0 drivers/base/driver.c:277 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1751 raw_release+0x1ae/0x2b0 drivers/usb/gadget/legacy/raw_gadget.c:463 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xdf/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4bb/0x570 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc5356cf749 RSP: 002b:00007ffff6578e48 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000003b361 RCX: 00007fc5356cf749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fc535927da0 R08: 0000000000000001 R09: 0000000af657913f R10: 0000001b2d620000 R11: 0000000000000246 R12: 00007fc535925fac R13: 00007fc535925fa0 R14: ffffffffffffffff R15: 00007ffff6578f60 Showing all locks held in the system: 6 locks held by kworker/1:0/23: 1 lock held by khungtaskd/30: #0: ffffffff892cd6e0 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] , at: rcu_read_lock include/linux/rcupdate.h:867 [inline] , at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 8 locks held by kworker/1:1/38: 4 locks held by kworker/u8:5/91: 6 locks held by kworker/1:2/1123: #0: ffff8881056ec148 ((wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc90001abfca0 ((work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88810a3c9198 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899 #3: ffff88813419d198 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006 #4: ffff88810aa96160 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006 #5: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #5: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11504 1 lock held by udevd/2860: #0: ffff888100ac5988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1183 2 locks held by getty/2922: #0: ffff888106b5f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211 4 locks held by udevd/5216: #0: ffff88812506d0a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182 #1: ffff88811bc08488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888134dd04b8 (kn->active#18){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888134dd04b8 (kn->active#18){.+.+}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff88813419d198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff88813419d198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 1 lock held by udevd/5226: #0: ffff888100ac5988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1183 4 locks held by kworker/0:3/5228: 6 locks held by kworker/1:3/5230: #0: ffff8881056ec148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000237fca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88810a331198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810a331198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899 #3: ffff888139d27198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888139d27198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9e0 drivers/usb/core/hub.c:2336 #4: ffff888105729160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff888105729160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #4: ffff888105729160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1302 #5: ffff888100ac5988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x100 fs/kernfs/dir.c:1715 4 locks held by kworker/1:4/5231: #0: ffff888100071948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000238fca0 (kernfs_notify_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff888100ac5ab8 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_notify_workfn+0xf7/0xb30 fs/kernfs/file.c:932 #3: ffff888100ac5988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_notify_workfn+0xff/0xb30 fs/kernfs/file.c:933 1 lock held by syz.4.350/6429: #0: ffffffff892d8e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 2 locks held by syz-executor/6433: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6444: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6447: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6464: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6466: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6483: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6494: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6496: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6514: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6516: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6533: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6544: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6546: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6564: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 2 locks held by syz-executor/6566: #0: ffffffff8a64fff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x31b/0x780 net/core/net_namespace.c:577 #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8a6666a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2083 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 7f 91 01 c3 cc cc cc cc 0f 1f 00 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 a3 27 0f 00 fb f4 fc f3 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc9000013fdf8 EFLAGS: 000002c2 RAX: 00000000005fb591 RBX: 0000000000000001 RCX: ffffffff8756ea29 RDX: 0000000000000000 RSI: ffffffff88d036ab RDI: ffffffff878a7200 RBP: ffffed10203d9750 R08: 0000000000000001 R09: ffffed103eae66c5 R10: ffff8881f573362b R11: ffff888101ecc528 R12: 0000000000000001 R13: ffff888101ecba80 R14: ffffffff8aa48bd0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888268cf5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563f77fcbaf8 CR3: 00000001173a8000 CR4: 00000000003506f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148