INFO: task kworker/1:5:19984 blocked for more than 140 seconds. Not tainted 4.14.261-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:5 D28872 19984 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 vhci_hcd: Failed attach request for unsupported USB speed: UNKNOWN schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 hub_port_connect drivers/usb/core/hub.c:4921 [inline] hub_port_connect_change drivers/usb/core/hub.c:5144 [inline] port_event drivers/usb/core/hub.c:5250 [inline] hub_event+0x15ea/0x3f60 drivers/usb/core/hub.c:5330 vhci_hcd: Failed attach request for unsupported USB speed: UNKNOWN process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 vhci_hcd: Failed attach request for unsupported USB speed: UNKNOWN ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 vhci_hcd: Failed attach request for unsupported USB speed: UNKNOWN Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 5 locks held by kworker/1:2/4315: #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/1:4/9025: #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/1:5/19984: #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 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.261-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 27309 Comm: kworker/u4:8 Not tainted 4.14.261-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff88805de74140 task.stack: ffff88805de80000 RIP: 0010:__lock_acquire+0x225/0x3f20 kernel/locking/lockdep.c:3396 RSP: 0018:ffff88805de87a38 EFLAGS: 00000002 RAX: ffffffff8b9e7150 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 1ffffffff11eef31 RSI: 0000000000000000 RDI: ffffffff88f77988 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: ffff88805de74140 R12: ffffffff88f77980 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff8bec9d40 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8aef033000 CR3: 0000000081d2d000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 rcu_lock_acquire include/linux/rcupdate.h:242 [inline] rcu_read_lock include/linux/rcupdate.h:629 [inline] batadv_nc_process_nc_paths.part.0+0xe3/0x350 net/batman-adv/network-coding.c:697 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:689 [inline] batadv_nc_worker+0x8b8/0xc50 net/batman-adv/network-coding.c:737 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 4b 8d 7c f4 08 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 5e 2a 00 00 4b 8b 44 f4 08 48 85 c0 0f 84 31 ff ff ff f0 ff 80 38 01 00 00 <49> 8d b3 80 08 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 f1 48 ---------------- Code disassembly (best guess): 0: 4b 8d 7c f4 08 lea 0x8(%r12,%r14,8),%rdi 5: 48 89 fa mov %rdi,%rdx 8: 48 c1 ea 03 shr $0x3,%rdx c: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 10: 0f 85 5e 2a 00 00 jne 0x2a74 16: 4b 8b 44 f4 08 mov 0x8(%r12,%r14,8),%rax 1b: 48 85 c0 test %rax,%rax 1e: 0f 84 31 ff ff ff je 0xffffff55 24: f0 ff 80 38 01 00 00 lock incl 0x138(%rax) * 2b: 49 8d b3 80 08 00 00 lea 0x880(%r11),%rsi <-- trapping instruction 32: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 39: fc ff df 3c: 48 89 f1 mov %rsi,%rcx 3f: 48 rex.W