FAT-fs (loop5): bogus number of reserved sectors FAT-fs (loop5): Can't find a valid FAT filesystem INFO: rcu_sched self-detected stall on CPU 1-....: (124999 ticks this GP) idle=67e/1/4611686018427387906 softirq=37021/37021 fqs=31235 (t=125000 jiffies g=19013 c=19012 q=631) NMI backtrace for cpu 1 CPU: 1 PID: 9938 Comm: syz-executor7 Not tainted 4.17.0-rc4+ #43 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+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline] rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376 print_cpu_stall kernel/rcu/tree.c:1525 [inline] check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593 __rcu_pending kernel/rcu/tree.c:3356 [inline] rcu_pending kernel/rcu/tree.c:3401 [inline] rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763 update_process_times+0x2d/0x70 kernel/time/timer.c:1636 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274 __run_hrtimer kernel/time/hrtimer.c:1398 [inline] __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x1/0x20 kernel/kcov.c:194 RSP: 0018:ffff88017b85f7d0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: 00000002894bebfa RCX: ffffc90004ec8000 RDX: 0000000000040000 RSI: fffffffd76b4190b RDI: 0000000000000edf RBP: ffff88017b85f848 R08: ffff8801c951a700 R09: 0000000000000006 R10: ffff8801c951a700 R11: 0000000000000000 R12: ffffc90001b9a000 R13: 0000000000000505 R14: fffffffd76b4190b R15: 00000000000000ff flush_echoes drivers/tty/n_tty.c:799 [inline] __receive_buf drivers/tty/n_tty.c:1615 [inline] n_tty_receive_buf_common+0x11d5/0x2c50 drivers/tty/n_tty.c:1709 n_tty_receive_buf+0x30/0x40 drivers/tty/n_tty.c:1738 tiocsti drivers/tty/tty_io.c:2171 [inline] tty_ioctl+0x7e7/0x1870 drivers/tty/tty_io.c:2557 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x16a0 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007fe435d87c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe435d886d4 RCX: 0000000000455979 RDX: 0000000020000080 RSI: 0000000000005412 RDI: 0000000000000016 RBP: 000000000072bf50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000033e R14: 00000000006f8e70 R15: 0000000000000001