vhci_hcd vhci_hcd.0: devid(0) speed(2) speed_str(full-speed) vhci_hcd: connection closed vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device INFO: task kworker/0:1:24 blocked for more than 140 seconds. Not tainted 4.14.218-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:1 D27232 24 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch syzkaller/managers/linux-4-14/kernel/kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 syzkaller/managers/linux-4-14/kernel/kernel/sched/core.c:3384 schedule+0x8d/0x1b0 syzkaller/managers/linux-4-14/kernel/kernel/sched/core.c:3428 usb_kill_urb.part.0+0x125/0x190 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/urb.c:691 usb_kill_urb+0x7c/0x90 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/urb.c:686 usb_start_wait_urb+0x209/0x440 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/message.c:62 usb_internal_control_msg syzkaller/managers/linux-4-14/kernel/drivers/usb/core/message.c:100 [inline] usb_control_msg+0x302/0x450 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/message.c:151 hub_port_init+0xfdc/0x2970 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:4555 hub_port_connect syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:5088 [inline] port_event syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:5194 [inline] hub_event+0x18fd/0x3d70 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:5274 process_one_work+0x793/0x14a0 syzkaller/managers/linux-4-14/kernel/kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 syzkaller/managers/linux-4-14/kernel/kernel/workqueue.c:2250 kthread+0x30d/0x420 syzkaller/managers/linux-4-14/kernel/kernel/kthread.c:232 ret_from_fork+0x24/0x30 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/entry_64.S:404 Showing all locks held in the system: 5 locks held by kworker/0:1/24: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 syzkaller/managers/linux-4-14/kernel/kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 syzkaller/managers/linux-4-14/kernel/kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock syzkaller/managers/linux-4-14/kernel/./include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3d70 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x18e8/0x3d70 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x15b/0x2970 syzkaller/managers/linux-4-14/kernel/drivers/usb/core/hub.c:4429 1 lock held by khungtaskd/1531: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:4548 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1531 Comm: khungtaskd Not tainted 4.14.218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 syzkaller/managers/linux-4-14/kernel/lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 syzkaller/managers/linux-4-14/kernel/lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace syzkaller/managers/linux-4-14/kernel/./include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks syzkaller/managers/linux-4-14/kernel/kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 syzkaller/managers/linux-4-14/kernel/kernel/hung_task.c:274 kthread+0x30d/0x420 syzkaller/managers/linux-4-14/kernel/kernel/kthread.c:232 ret_from_fork+0x24/0x30 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4615 Comm: systemd-journal Not tainted 4.14.218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a1aea600 task.stack: ffff8880a1af0000 RIP: 0010:__lock_release syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:3804 [inline] RIP: 0010:lock_release+0x399/0x870 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:4017 RSP: 0018:ffff8880a1af7b20 EFLAGS: 00000097 RAX: 0000000000000004 RBX: 1ffff1101435ef67 RCX: 1ffff1101435d5d6 RDX: 1ffffffff17d69a8 RSI: 0000000000000002 RDI: ffff8880a1aea600 RBP: 0000000000000001 R08: ffffffff8b9af2c8 R09: 0000000000000001 R10: 0000000000000000 R11: ffff8880a1aea600 R12: f17bcfabce23016f R13: 0000000000000003 R14: ffff8880a1aea600 R15: 0000000000000002 FS: 00007f47c21298c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f47bf76e000 CR3: 00000000a1950000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock syzkaller/managers/linux-4-14/kernel/./include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock+0x17/0x40 syzkaller/managers/linux-4-14/kernel/kernel/locking/spinlock.c:184 devkmsg_poll+0x11a/0x1f0 syzkaller/managers/linux-4-14/kernel/kernel/printk/printk.c:942 ep_item_poll syzkaller/managers/linux-4-14/kernel/fs/eventpoll.c:885 [inline] ep_send_events_proc+0x1f4/0x9c0 syzkaller/managers/linux-4-14/kernel/fs/eventpoll.c:1675 ep_scan_ready_list+0x1c6/0x7e0 syzkaller/managers/linux-4-14/kernel/fs/eventpoll.c:711 ep_send_events syzkaller/managers/linux-4-14/kernel/fs/eventpoll.c:1723 [inline] ep_poll+0x234/0xa50 syzkaller/managers/linux-4-14/kernel/fs/eventpoll.c:1848 SYSC_epoll_wait syzkaller/managers/linux-4-14/kernel/fs/eventpoll.c:2195 [inline] SyS_epoll_wait+0x150/0x1a0 syzkaller/managers/linux-4-14/kernel/fs/eventpoll.c:2160 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f47c13f32e3 RSP: 002b:00007ffe33af7108 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 000055a39deee1e0 RCX: 00007f47c13f32e3 RDX: 0000000000000013 RSI: 00007ffe33af7110 RDI: 0000000000000008 RBP: 00007ffe33af7300 R08: 00007ffe33b4f000 R09: 00000180c5cb5c08 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe33af7110 R13: 0000000000000001 R14: 0000000000000000 R15: 0005bb7b09c70bf0 Code: 38 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 41 83 e5 07 48 c1 ea 03 41 83 c5 03 0f b6 04 02 41 38 c5 7c 08 84 c0 0f 85 b8 02 00 00 <8b> 15 71 96 a9 0a 85 d2 0f 84 6a 01 00 00 65 48 8b 2c 25 80 df