rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=196/1/0x4000000000000002 softirq=57079/57079 fqs=5211 
rcu: 	 (t=10500 jiffies g=85009 q=2827)
NMI backtrace for cpu 0
CPU: 0 PID: 24592 Comm: syz-executor0 Not tainted 4.20.0+ #396
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d3/0x2c6 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1c2/0x22c 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:1211
 print_cpu_stall.cold.68+0x218/0x40a kernel/rcu/tree.c:1348
 check_cpu_stall kernel/rcu/tree.c:1422 [inline]
 rcu_pending kernel/rcu/tree.c:3018 [inline]
 rcu_check_callbacks+0xac1/0x1410 kernel/rcu/tree.c:2521
 update_process_times+0x2d/0x70 kernel/time/timer.c:1635
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:161
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101
Code: 5d c3 66 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 78 01 80 7e 81 e2 00 01 1f 00 75 2b 8b 90 d8 12 00 00 <83> fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48
RSP: 0018:ffff888060796e18 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff8880a4eb8240 RBX: 00000000ffffffff RCX: ffffc90005dd1000
RDX: 0000000000000002 RSI: ffffffff81e2e0e2 RDI: ffffed100c0f2d86
RBP: ffff888060796e18 R08: ffff8880a4eb8240 R09: ffffed1015cc5b8f
R10: 0000000000000003 R11: ffff8880ae62dc7b R12: 0000000000000001
R13: 0000000000000200 R14: 1ffff1100c0f2ddf R15: dffffc0000000000
 grow_buffers fs/buffer.c:998 [inline]
 __getblk_slow fs/buffer.c:1043 [inline]
 __getblk_gfp+0x2d2/0xd50 fs/buffer.c:1320
 __bread_gfp+0x2d/0x300 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+0x15e4/0x5160 fs/namei.c:3534
 do_filp_open+0x255/0x380 fs/namei.c:3564
 do_sys_open+0x568/0x780 fs/open.c:1063
 ksys_open include/linux/syscalls.h:1298 [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: 0033:0x457ec9
Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f171c7a0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457ec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f171c7a16d4
R13: 00000000004be411 R14: 00000000004ce608 R15: 00000000ffffffff