INFO: rcu_sched self-detected stall on CPU 0-....: (124929 ticks this GP) idle=c7e/140000000000001/0 softirq=46979/46979 fqs=31175 (t=125000 jiffies g=25567 c=25566 q=517) NMI backtrace for cpu 0 CPU: 0 PID: 19103 Comm: syz-executor2 Not tainted 4.15.0-rc4+ #144 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+0x186/0x1d9 kernel/rcu/tree.c:1459 print_cpu_stall kernel/rcu/tree.c:1608 [inline] check_cpu_stall.isra.61+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+0x358/0xe20 kernel/time/hrtimer.c:1275 hrtimer_interrupt+0x1c2/0x5e0 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+0xa9/0xb0 arch/x86/entry/entry_64.S:904 RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x50 kernel/kcov.c:94 RSP: 0018:ffff8801ce777970 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff11 RAX: ffff8801cd422180 RBX: ffffc90001260060 RCX: ffffffff8286f99c RDX: 0000000000010000 RSI: ffffc90002cce000 RDI: ffffc90001261260 RBP: ffff8801ce777970 R08: 1ffff10039ceee5f R09: 0000000000000004 R10: ffff8801ce7777c0 R11: 0000000000000003 R12: ffffc9000125f000 R13: 00000004924e8d76 R14: 0000000020fe9000 R15: ffff8801cc467838 inq_canon drivers/tty/n_tty.c:2412 [inline] n_tty_ioctl+0x266/0x2d0 drivers/tty/n_tty.c:2429 tty_ioctl+0x336/0x1610 drivers/tty/tty_io.c:2638 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 C_SYSC_ioctl fs/compat_ioctl.c:1495 [inline] compat_SyS_ioctl+0x4ef/0x2a30 fs/compat_ioctl.c:1419 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:125 RIP: 0023:0xf7f9bc79 RSP: 002b:00000000f779708c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 000000000000541b RDX: 0000000020fe9000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000