vhci_hcd vhci_hcd.0: port 0 already used INFO: task kworker/0:3:4646 blocked for more than 140 seconds. Not tainted 4.14.259-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:3 D26584 4646 2 0x80000000 Workqueue: usb_hub_wq hub_event vhci_hcd vhci_hcd.0: port 0 already used Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 vhci_hcd vhci_hcd.0: port 0 already used schedule+0x8d/0x1b0 kernel/sched/core.c:3431 usb_kill_urb.part.0+0x125/0x190 drivers/usb/core/urb.c:691 usb_kill_urb+0x7c/0x90 drivers/usb/core/urb.c:686 usb_start_wait_urb+0x209/0x440 drivers/usb/core/message.c:62 usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x302/0x450 drivers/usb/core/message.c:151 hub_port_init+0xf27/0x28b0 drivers/usb/core/hub.c:4599 hub_port_connect drivers/usb/core/hub.c:4954 [inline] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] port_event drivers/usb/core/hub.c:5250 [inline] hub_event+0x1948/0x3f60 drivers/usb/core/hub.c:5330 vhci_hcd vhci_hcd.0: port 0 already used process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 vhci_hcd vhci_hcd.0: port 0 already used worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 vhci_hcd vhci_hcd.0: port 0 already used 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: 5 locks held by kworker/0:0/3: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 1 lock held by khungtaskd/1534: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 5 locks held by kworker/0:2/3304: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 5 locks held by kworker/0:3/4646: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 5 locks held by kworker/1:3/8985: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 5 locks held by kworker/0:4/9006: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 5 locks held by kworker/0:5/24563: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1082 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3f60 drivers/usb/core/hub.c:5276 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2936 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4920 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x15c0/0x3f60 drivers/usb/core/hub.c:5330 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4921 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] port_event drivers/usb/core/hub.c:5250 [inline] #4: (hcd->address0_mutex){+.+.}, at: [] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1534 Comm: khungtaskd Not tainted 4.14.259-syzkaller #0 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 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: 4610 Comm: systemd-journal Not tainted 4.14.259-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a1dbc4c0 task.stack: ffff8880a1dc0000 RIP: 0010:___bpf_prog_run+0x10a5/0x5a70 kernel/bpf/core.c:1256 RSP: 0018:ffff8880a1dc7a48 EFLAGS: 00000a02 RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: ffff8880a1dc7e68 RDX: 1ffff110143b8f6b RSI: ffffc90001a4f030 RDI: ffffffff878f06c8 RBP: ffff8880a1dc7b58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff878f0220 R13: 1ffff110143b8f50 R14: ffffc90001a4f208 R15: 0000000000000095 FS: 00007fce61b268c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fce5ef59028 CR3: 00000000a3082000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: Code: 84 d2 0f 85 cd 34 00 00 41 8b 46 04 89 44 24 08 e9 8b f2 ff ff e8 7c e7 f6 ff 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 5d 45 00 00 44 8b 65 00 e9 25 f0 ff ff e8 53 ---------------- Code disassembly (best guess): 0: 84 d2 test %dl,%dl 2: 0f 85 cd 34 00 00 jne 0x34d5 8: 41 8b 46 04 mov 0x4(%r14),%eax c: 89 44 24 08 mov %eax,0x8(%rsp) 10: e9 8b f2 ff ff jmpq 0xfffff2a0 15: e8 7c e7 f6 ff callq 0xfff6e796 1a: 48 89 ea mov %rbp,%rdx 1d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 24: fc ff df 27: 48 c1 ea 03 shr $0x3,%rdx * 2b: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2f: 0f 85 5d 45 00 00 jne 0x4592 35: 44 8b 65 00 mov 0x0(%rbp),%r12d 39: e9 25 f0 ff ff jmpq 0xfffff063 3e: e8 .byte 0xe8 3f: 53 push %rbx