INFO: task syz-executor.1:5662 blocked for more than 143 seconds. Not tainted 5.4.0-rc5+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27608 5662 1749 0x00000004 Call Trace: schedule+0xca/0x250 kernel/sched/core.c:4136 schedule_timeout+0x440/0xb20 kernel/time/timer.c:1895 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+0x87b/0xa20 drivers/usb/misc/ldusb.c:576 __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:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459f49 Code: 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 <0f> 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7 10 0f RSP: 002b:00007fa9942acc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f49 RDX: 0000000000000044 RSI: 0000000020000000 RDI: 0000000000000007 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa9942ad6d4 R13: 00000000004ca87c R14: 00000000004e2d18 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: ffffffff86cfe8a0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:5335 1 lock held by rsyslogd/1598: #0: ffff8881d3028fe0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:801 2 locks held by getty/1688: #0: ffff8881d18c4090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004512e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1689: #0: ffff8881d19e2090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004552e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1690: #0: ffff8881d1816090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1691: #0: ffff8881d19e3090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004592e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1692: #0: ffff8881d19d4090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004492e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1693: #0: ffff8881d18c5090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc9000045d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1694: #0: ffff8881d3b5c090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc9000042d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.1/5662: #0: ffff8881da3d5c60 (&dev->mutex#3){+.+.}, at: ld_usb_write+0x111/0xa20 drivers/usb/misc/ldusb.c:538 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.4.0-rc5+ #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