vhci_hcd vhci_hcd.0: pdev(4) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(5) speed_str(super-speed) INFO: task kworker/0:2:3626 blocked for more than 140 seconds. vhci_hcd vhci_hcd.0: Device attached Not tainted 4.14.232-syzkaller #0 vhci_hcd: cannot find a urb of seqnum 0 max seqnum 3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. vhci_hcd: stop threads kworker/0:2 D27720 3626 2 0x80000000 vhci_hcd: release socket Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 vhci_hcd: disconnect device hub_port_init+0x15b/0x2970 drivers/usb/core/hub.c:4429 hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x18fd/0x3d70 drivers/usb/core/hub.c:5274 vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(3) process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 vhci_hcd vhci_hcd.0: devid(0) speed(5) speed_str(super-speed) vhci_hcd vhci_hcd.0: Device attached worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Showing all locks held in the system: vhci_hcd: connection closed vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device vhci_hcd: Failed attach request for unsupported USB speed: UNKNOWN vhci_hcd: Failed attach request for unsupported USB speed: UNKNOWN 5 locks held by kworker/1:0/18: vhci_hcd: Failed attach request for unsupported USB speed: UNKNOWN #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3d70 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x18e8/0x3d70 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x15b/0x2970 drivers/usb/core/hub.c:4429 1 lock held by khungtaskd/1519: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 3 locks held by kworker/1:2/3486: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3d70 drivers/usb/core/hub.c:5220 5 locks held by kworker/0:2/3626: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3d70 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x18e8/0x3d70 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x15b/0x2970 drivers/usb/core/hub.c:4429 ============================================= vhci_hcd vhci_hcd.0: pdev(3) rhport(0) sockfd(3) vhci_hcd vhci_hcd.0: devid(0) speed(5) speed_str(super-speed) vhci_hcd vhci_hcd.0: Device attached NMI backtrace for cpu 0 vhci_hcd: cannot find a urb of seqnum 0 max seqnum 0 CPU: 0 PID: 1519 Comm: khungtaskd Not tainted 4.14.232-syzkaller #0 vhci_hcd: stop threads Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 vhci_hcd: release socket trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2849 Comm: kworker/u4:4 Not tainted 4.14.232-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usbip_event event_handler task: ffff8880ac76c5c0 task.stack: ffff8880ac778000 RIP: 0010:rebalance_domains+0x513/0x8a0 kernel/sched/fair.c:8813 RSP: 0018:ffff8880ba507e68 EFLAGS: 00000246 RAX: 1ffff11016bf2f08 RBX: 0000000000000001 RCX: 000000010000a246 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000080 RBP: 000000000001eb5b R08: 0000000000000001 R09: 000000000000023c R10: 0000000000000001 R11: ffff8880b5f97840 R12: ffff8880b5f97898 R13: fffffbfff11c1b30 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1681173000 CR3: 000000007ce7a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1685 [inline] RIP: 0010:vprintk_emit+0x549/0x620 kernel/printk/printk.c:1922 RSP: 0018:ffff8880ac77fb78 EFLAGS: 00000297 ORIG_RAX: ffffffffffffff10 RAX: ffff8880ac76c5c0 RBX: 1ffffffff11e1259 RCX: 1ffff110158ed9d7 RDX: 0000000000000000 RSI: ffff8880ac76ce98 RDI: 0000000000000297 RBP: ffff8880ac77fbb0 R08: ffffffff8b99f4d0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000018 R13: ffff8880b2d46200 R14: 0000000000000297 R15: 0000000000000000 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1996 vhci_shutdown_connection.cold+0x10e/0x853 drivers/usb/usbip/vhci_hcd.c:1050 event_handler+0x1da/0x4d0 drivers/usb/usbip/usbip_event.c:93 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 48 89 4c 24 08 89 5c 24 04 4c 89 f8 48 c1 e8 03 42 80 3c 30 00 0f 85 64 02 00 00 4d 8b 3f 4d 85 ff 0f 85 ae fc ff ff 8b 74 24 10 <49> 89 ef 48 8b 6c 24 20 85 f6 0f 84 5b fd ff ff 49 81 ff 20 a1