rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=0fe/1/0x4000000000000002 softirq=80906/80907 fqs=4779 rcu: (t=10500 jiffies g=120917 q=3296) NMI backtrace for cpu 0 CPU: 0 PID: 376 Comm: syz-executor0 Not tainted 4.20.0-rc5+ #366 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:164 [inline] rcu_dump_cpu_stacks+0x16f/0x1bc kernel/rcu/tree.c:1195 print_cpu_stall.cold.67+0x1f3/0x3c7 kernel/rcu/tree.c:1334 check_cpu_stall kernel/rcu/tree.c:1408 [inline] rcu_pending kernel/rcu/tree.c:2961 [inline] rcu_check_callbacks+0xf3b/0x13f0 kernel/rcu/tree.c:2506 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+0x41c/0x10d0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline] smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] RIP: 0010:lock_acquire+0x268/0x520 kernel/locking/lockdep.c:3847 Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 44 02 00 00 48 83 3d 07 14 f0 07 00 0f 84 c3 01 00 00 48 8b bd 20 ff ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 RSP: 0018:ffff88817fb4eb68 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 1ffff1102ff69d72 RCX: 0000000000000000 RDX: 1ffffffff12a401e RSI: 0000000000000000 RDI: 0000000000000286 RBP: ffff88817fb4ec58 R08: ffff888188a289d8 R09: 0000000000000008 R10: 000000000000679f R11: ffff888188a280c0 R12: ffff888188a280c0 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] __find_get_block_slow fs/buffer.c:209 [inline] __find_get_block+0x661/0xf20 fs/buffer.c:1294 __getblk_slow fs/buffer.c:1039 [inline] __getblk_gfp+0x2b3/0xd50 fs/buffer.c:1320 __bread_gfp+0x2d/0x310 fs/buffer.c:1354 sb_bread include/linux/buffer_head.h:307 [inline] fat__get_entry+0x5a6/0xa40 fs/fat/dir.c:101 fat_get_entry fs/fat/dir.c:129 [inline] fat_search_long+0x33b/0x1570 fs/fat/dir.c:479 vfat_find+0x16d/0x1a0 fs/fat/namei_vfat.c:697 vfat_lookup+0x107/0x640 fs/fat/namei_vfat.c:711 lookup_open+0x72e/0x1b90 fs/namei.c:3213 do_last fs/namei.c:3324 [inline] path_openat+0x15e4/0x5150 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 ksys_open include/linux/syscalls.h:1279 [inline] __do_sys_creat fs/open.c:1121 [inline] __se_sys_creat fs/open.c:1119 [inline] __x64_sys_creat+0x61/0x80 fs/open.c:1119 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc7ad3bac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc7ad3bb6d4 R13: 00000000004bdbef R14: 00000000004cced0 R15: 00000000ffffffff sched: RT throttling activated