INFO: task syz-executor.3:3326 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.3 D28272 3326 1749 0x00004004 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:00007f2495683c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f49 RDX: 00000000000000e3 RSI: 0000000020000100 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f24956846d4 R13: 00000000004ca679 R14: 00000000004e2808 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/1597: #0: ffff8881d46565e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:801 2 locks held by getty/1689: #0: ffff8881d18f4090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004612e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1690: #0: ffff8881d1ac1090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc9000047d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1691: #0: ffff8881d15c6090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004752e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1692: #0: ffff8881d1bb0090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004712e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1693: #0: ffff8881d20ff090 (&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/1694: #0: ffff8881d1bb2090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004792e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1695: #0: ffff8881d1917090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004452e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.3/3326: #0: ffff8881c751f460 (&dev->mutex#4){+.+.}, at: ld_usb_write+0x111/0xa20 drivers/usb/misc/ldusb.c:538 ============================================= NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.4.0-rc5+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_dynticks_eqs_exit+0x0/0x60 kernel/rcu/tree.c:253 Code: d4 7e 48 8d bb e0 00 00 00 be 04 00 00 00 e8 97 b2 38 00 b8 04 00 00 00 f0 0f c1 83 e0 00 00 00 a8 02 74 02 5b c3 0f 0b 5b c3 <55> 53 48 c7 c3 80 2b 03 00 65 48 03 1d 57 ff d4 7e 48 8d ab e0 00 RSP: 0018:ffff8881db309f50 EFLAGS: 00000046 RAX: 0000000000098390 RBX: ffff8881db332b80 RCX: ffffffff812d916c RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8881db332c60 RBP: ffff8881db332c58 R08: 0000000000000000 R09: ffffed103b66658d R10: ffffed103b66658c R11: ffff8881db332c63 R12: ffff8881db332c60 R13: ffffffff86b0d6c8 R14: 0000000000000001 R15: ffff8881db332b80 FS: 0000000000000000(0000) GS:ffff8881db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42048b000 CR3: 00000001d3f17000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_nmi_enter_common kernel/rcu/tree.c:821 [inline] rcu_irq_enter+0x30e/0x520 kernel/rcu/tree.c:870 irq_enter+0x6/0xd0 kernel/softirq.c:347 scheduler_ipi+0x24a/0x590 kernel/sched/core.c:2337 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:854 RIP: 0010:default_idle+0x28/0x2e0 arch/x86/kernel/process.c:581 Code: 90 90 41 56 41 55 65 44 8b 2d 74 ee 91 7a 41 54 55 53 0f 1f 44 00 00 e8 26 ad d3 fb e9 07 00 00 00 0f 00 2d aa 93 52 00 fb f4 <65> 44 8b 2d 50 ee 91 7a 0f 1f 44 00 00 5b 5d 41 5c 41 5d 41 5e c3 RSP: 0018:ffff8881da22fdc8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02 RAX: 0000000000000007 RBX: ffff8881da213000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff8881da21384c RBP: ffffed103b442600 R08: ffff8881da213000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3b6/0x500 kernel/sched/idle.c:263 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:355 start_secondary+0x27d/0x330 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241