INFO: task syz-executor.1:6171 blocked for more than 143 seconds. Not tainted 5.3.0-rc7+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28344 6171 1757 0x00004004 Call Trace: schedule+0xca/0x250 kernel/sched/core.c:3947 schedule_timeout+0x440/0xb20 kernel/time/timer.c:1807 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion_timeout+0x282/0x3e0 kernel/sched/completion.c:155 usb_start_wait_urb+0x14b/0x2b0 drivers/usb/core/message.c:62 usb_internal_control_msg drivers/usb/core/message.c:101 [inline] usb_control_msg+0x31c/0x4a0 drivers/usb/core/message.c:152 ld_usb_write+0x856/0xa10 drivers/usb/misc/ldusb.c:577 __vfs_write+0x76/0x100 fs/read_write.c:494 vfs_write+0x262/0x5c0 fs/read_write.c:558 ksys_write+0x1e8/0x250 fs/read_write.c:611 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4598e9 Code: 70 c0 00 48 83 fb 10 7c 54 48 89 f7 48 83 fb 20 0f 87 8d 00 00 00 48 8d 44 1e f0 eb 15 f3 0f 6f 0f 66 0f 74 c8 66 0f d7 d1 0f d2 75 25 48 83 c7 10 48 39 c7 72 e6 48 89 c7 f3 0f 6f 08 66 0f RSP: 002b:00007f71d45d3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9 RDX: 00000000000000d3 RSI: 00000000200001c0 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f71d45d46d4 R13: 00000000004c9a9b R14: 00000000004e11a8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: 00000000aea0a4f7 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:5254 1 lock held by rsyslogd/1609: #0: 0000000011f359b1 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:801 2 locks held by getty/1699: #0: 00000000d23d7106 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 0000000090ae8283 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1700: #0: 00000000350bde95 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000354b0a6a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1701: #0: 000000002de83bec (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 0000000006351cf8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1702: #0: 00000000638753b2 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000a9117cd8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1703: #0: 00000000f95c6d3e (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000009c06566c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1704: #0: 00000000d383b13c (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 0000000082e4b953 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1705: #0: 000000006cc539bb (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000003d471ddf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 5 locks held by kworker/0:5/2771: #0: 00000000f7fed5f8 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: 00000000f7fed5f8 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000f7fed5f8 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 00000000f7fed5f8 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 00000000f7fed5f8 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: 00000000f7fed5f8 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: 00000000f7fed5f8 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x827/0x1530 kernel/workqueue.c:2240 #1: 00000000e71ebc39 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85b/0x1530 kernel/workqueue.c:2244 #2: 0000000023974e1c (&dev->mutex){....}, at: device_lock include/linux/device.h:1223 [inline] #2: 0000000023974e1c (&dev->mutex){....}, at: hub_event+0x17c/0x3640 drivers/usb/core/hub.c:5387 #3: 000000007cd083c6 (&dev->mutex){....}, at: device_lock include/linux/device.h:1223 [inline] #3: 000000007cd083c6 (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 #4: 000000007eb5708c (&dev->mutex){....}, at: device_lock include/linux/device.h:1223 [inline] #4: 000000007eb5708c (&dev->mutex){....}, at: __device_attach+0x7b/0x360 drivers/base/dd.c:871 1 lock held by syz-executor.1/6171: #0: 00000000c7d42ef9 (&dev->mutex#3){+.+.}, at: ld_usb_write+0x111/0xa10 drivers/usb/misc/ldusb.c:539 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x55/0x96 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1c7 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x9a4/0xe50 kernel/hung_task.c:289 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0x28/0x2e0 arch/x86/kernel/process.c:580