INFO: task kworker/1:3:5846 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:24808 pid:5846 tgid:5846 ppid:2 task_flags:0x4208060 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 usb_kill_urb+0x1be/0x2d0 drivers/usb/core/urb.c:718 usb_start_wait_urb+0x18c/0x4c0 drivers/usb/core/message.c:65 usb_internal_control_msg drivers/usb/core/message.c:103 [inline] usb_control_msg+0x232/0x3e0 drivers/usb/core/message.c:154 get_bMaxPacketSize0 drivers/usb/core/hub.c:4850 [inline] hub_port_init+0x11e4/0x2800 drivers/usb/core/hub.c:5111 hub_port_connect drivers/usb/core/hub.c:5495 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2532/0x4a20 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 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:5/131: #0: ffff88801a069148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a069148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90002e37ba0 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90002e37ba0 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880b8925958 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline] #2: ffff8880b8925958 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085 #3: ffffffff99a5f528 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xbb/0x420 lib/debugobjects.c:818 #4: ffffffff8dde8948 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145 2 locks held by getty/5586: #0: ffff888033a3b0a0 (&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 5 locks held by kworker/1:3/5846: #0: ffff8881404a8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8881404a8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003c3fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003c3fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888145fa1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff888145fa1198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff888145fa4518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline] #3: ffff888145fa4518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline] #3: ffff888145fa4518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #3: ffff888145fa4518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #3: ffff888145fa4518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b8/0x4a20 drivers/usb/core/hub.c:5952 #4: ffff8880277bb668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #4: ffff8880277bb668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #4: ffff8880277bb668 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #4: ffff8880277bb668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e5/0x4a20 drivers/usb/core/hub.c:5952 ============================================= 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 10/25/2025 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: 7658 Comm: syz-executor.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:mark_usage kernel/locking/lockdep.c:4630 [inline] RIP: 0010:__lock_acquire+0x626/0xd20 kernel/locking/lockdep.c:5191 Code: 00 00 00 65 8b 0d a6 31 d1 10 a9 00 00 03 00 74 38 85 c9 74 1d 48 8b 3c 24 4c 89 f6 ba 01 00 00 00 e8 0e 26 00 00 48 8b 3c 24 <85> c0 0f 84 77 06 00 00 83 bf 14 0b 00 00 00 74 55 48 8b 3c 24 4c RSP: 0018:ffffc90000a08c30 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff931744d0 RDX: 0000000000000001 RSI: ffff888032740c20 RDI: ffff888032740000 RBP: 0000000000000054 R08: 0000000000000000 R09: ffffffff81ae5e27 R10: dffffc0000000000 R11: fffff520001411b0 R12: 0000000000024000 R13: 0000000000000000 R14: ffff888032740c20 R15: ffff888032740b30 FS: 00007f62409b36c0(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f62409b2f60 CR3: 000000005dffc000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access+0xcf/0x1c0 include/linux/seqlock.h:72 ktime_get_update_offsets_now+0x67/0x3d0 kernel/time/timekeeping.c:2556 hrtimer_update_base kernel/time/hrtimer.c:633 [inline] hrtimer_interrupt+0x132/0xaa0 kernel/time/hrtimer.c:1885 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2034 [inline] RIP: 0010:vprintk_emit+0x49d/0x590 kernel/printk/printk.c:2422 Code: 0f 84 34 ff ff ff e8 c2 eb 1f 00 fb eb 44 e8 ba eb 1f 00 e8 35 5a a6 09 4d 85 f6 74 94 e8 ab eb 1f 00 fb 48 c7 c7 c0 16 f3 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 4b 39 RSP: 0018:ffffc9000d1ff680 EFLAGS: 00000293 RAX: ffffffff81a017e5 RBX: ffffffff81a0163e RCX: ffff888032740000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df316c0 RBP: ffffc9000d1ff790 R08: ffffffff8f7ce977 R09: 1ffffffff1ef9d2e R10: dffffc0000000000 R11: fffffbfff1ef9d2f R12: 0000000000000000 R13: 0000000000000028 R14: 0000000000000200 R15: 1ffff92001a3fed4 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925 _dev_err+0x10a/0x160 drivers/base/core.c:4980 attach_store+0x965/0xab0 drivers/usb/usbip/vhci_sysfs.c:407 kernfs_fop_write_iter+0x3af/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f623fc7b86f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 80 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 0c 81 02 00 48 RSP: 002b:00007f62409b2ae0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f623fc7b86f RDX: 0000000000000007 RSI: 00007f62409b2b30 RDI: 0000000000000005 RBP: 00007f623fcd9180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000007 R13: 00007f62409b2b30 R14: 00007f623fd9bf80 R15: 00007ffcd557da48