INFO: task syz-executor.1:4141 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 D28904 4141 1743 0x00000004 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:00007fbcbdbbcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598e9 RDX: 0000000000000096 RSI: 0000000020000140 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbcbdbbd6d4 R13: 00000000004c9a9b R14: 00000000004e11a8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: 000000001753b213 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:5254 1 lock held by rsyslogd/1600: #0: 0000000091751c8b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:801 2 locks held by getty/1690: #0: 00000000600784f7 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000730979bd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1691: #0: 00000000334a4b62 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000ab54afb5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1692: #0: 0000000014466ed8 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000e215b009 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1693: #0: 000000006d5452ee (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000001320b030 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1694: #0: 00000000359f000e (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000003193627d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1695: #0: 00000000b11ed7cf (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000ea8c1b36 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1696: #0: 0000000008c8e1db (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000195b6652 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.1/4141: #0: 000000004bb8dd7c (&dev->mutex#3){+.+.}, at: ld_usb_write+0x111/0xa10 drivers/usb/misc/ldusb.c:539 ============================================= NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0x28/0x2e0 arch/x86/kernel/process.c:580