Buffer I/O error on dev loop0, logical block 0, async page read INFO: rcu_sched self-detected stall on CPU 1-....: (124999 ticks this GP) idle=ca6/140000000000001/0 softirq=23381/23381 fqs=31226 (t=125000 jiffies g=12473 c=12472 q=941) NMI backtrace for cpu 1 CPU: 1 PID: 7515 Comm: syz-executor4 Not tainted 4.15.0-rc1+ #199 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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+0x186/0x1d5 kernel/rcu/tree.c:1459 print_cpu_stall kernel/rcu/tree.c:1608 [inline] check_cpu_stall.isra.64+0xbb8/0x15b0 kernel/rcu/tree.c:1676 __rcu_pending kernel/rcu/tree.c:3440 [inline] rcu_pending kernel/rcu/tree.c:3502 [inline] rcu_check_callbacks+0x256/0xd00 kernel/rcu/tree.c:2842 update_process_times+0x30/0x60 kernel/time/timer.c:1630 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162 tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1166 __run_hrtimer kernel/time/hrtimer.c:1211 [inline] __hrtimer_run_queues+0x349/0xe10 kernel/time/hrtimer.c:1275 hrtimer_interrupt+0x1d4/0x5f0 kernel/time/hrtimer.c:1309 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:795 RIP: 0010:__sanitizer_cov_trace_pc+0x4c/0x50 kernel/kcov.c:111 RSP: 0018:ffff8801c8bffb40 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11 RAX: 0000000000010000 RBX: ffffc9000159a060 RCX: ffffffff82864b7c RDX: 0000000000010000 RSI: ffffc900034f0000 RDI: ffffc9000159b260 RBP: ffff8801c8bffb88 R08: 0000000000000001 R09: 0000000000000004 R10: 0000000000000000 R11: ffffffff87489d60 R12: ffffc90001599000 R13: 00000004771ffbe3 R14: 00000000208f4000 R15: ffff8801c694e478 tty_ioctl+0x32e/0x15f0 drivers/tty/tty_io.c:2638 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x4529d9 RSP: 002b:00007f8c4ded4c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8c4ded49a0 RCX: 00000000004529d9 RDX: 00000000208f4000 RSI: 000000000000541b RDI: 0000000000000014 RBP: 00007f8c4ded4990 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b71e6 R13: 00007f8c4ded4ac8 R14: 00000000004b71ef R15: 0000000000000000