INFO: task kworker/1:5:29353 blocked for more than 140 seconds. Not tainted 4.14.232-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:5 D28424 29353 2 0x80000000 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 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 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 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 1 lock held by syz-executor.4/7985: #0: (rcu_preempt_state.exp_mutex){+.+.}, at: [] exp_funnel_lock kernel/rcu/tree_exp.h:272 [inline] #0: (rcu_preempt_state.exp_mutex){+.+.}, at: [] _synchronize_rcu_expedited+0x2c2/0x770 kernel/rcu/tree_exp.h:596 5 locks held by kworker/1:5/29353: #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 5 locks held by kworker/1:0/2354: #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 2 locks held by kworker/1:4/23588: #0: ("events"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&rew.rew_work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1533 Comm: khungtaskd Not tainted 4.14.232-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: 7985 Comm: syz-executor.4 Not tainted 4.14.232-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880790d8000 task.stack: ffff8880790e0000 RIP: 0010:memset+0x0/0x40 mm/kasan/kasan.c:284 RSP: 0018:ffff8880790e7450 EFLAGS: 00010802 RAX: ffffed100f21ce8f RBX: ffff8880790e7570 RCX: ffff8880790e7570 RDX: 0000000000000058 RSI: 0000000000000000 RDI: ffff8880790e7500 RBP: 1ffff1100f21ce8f R08: ffffffff8ba3e66c R09: 00000000000024e4 R10: 0000000000000001 R11: ffff8880790d8000 R12: ffff8880790d8000 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8880790e7500 FS: 0000000001c93400(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc91db24018 CR3: 00000000a14cc000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: memset include/linux/string.h:361 [inline] __unwind_start+0x66/0x930 arch/x86/kernel/unwind_orc.c:511 unwind_start arch/x86/include/asm/unwind.h:60 [inline] __save_stack_trace+0x63/0x160 arch/x86/kernel/stacktrace.c:43 save_trace+0xd6/0x290 kernel/locking/lockdep.c:407 check_prev_add kernel/locking/lockdep.c:1953 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x35e5/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 prepare_to_wait_event+0x5b/0x6a0 kernel/sched/wait.c:270 _synchronize_rcu_expedited+0x532/0x770 kernel/rcu/tree_exp.h:615 synchronize_rcu+0x98/0x130 kernel/rcu/tree_plugin.h:762 hci_conn_hash_del include/net/bluetooth/hci_core.h:712 [inline] hci_conn_cleanup+0x149/0x500 net/bluetooth/hci_conn.c:123 hci_conn_del+0x253/0x6f0 net/bluetooth/hci_conn.c:611 hci_conn_hash_flush+0x19c/0x260 net/bluetooth/hci_conn.c:1394 hci_dev_do_close+0x535/0xca0 net/bluetooth/hci_core.c:1622 hci_unregister_dev+0x17f/0x8c0 net/bluetooth/hci_core.c:3193 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:354 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa44/0x2850 kernel/exit.c:868 do_group_exit+0x100/0x2e0 kernel/exit.c:965 SYSC_exit_group kernel/exit.c:976 [inline] SyS_exit_group+0x19/0x20 kernel/exit.c:974 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4665f9 RSP: 002b:00007ffce48a6118 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000293c RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 0000000000000000 R08: 0000000000000014 R09: 000000000000293c R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004bfe2c R13: 0000000000000000 R14: 0000000000000014 R15: 00007ffce48a6310 Code: 5b 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 fe 48 89 e5 48 29 ee 48 39 fd 77 09 48 89 ef 5d e9 c8 fd ff ff 0f 0b 5d c3 0f 1f 40 00 <41> 55 41 89 f5 41 54 49 89 d4 ba 01 00 00 00 55 48 8b 4c 24 18