rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=c06/1/0x4000000000000002 softirq=204256/204256 fqs=5233 
rcu: 	 (t=10500 jiffies g=228821 q=759)
NMI backtrace for cpu 0
CPU: 0 PID: 22880 Comm: syz-executor5 Not tainted 4.20.0-rc5+ #368
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+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
 </IRQ>
RIP: 0010:check_preemption_disabled+0x33/0x280 lib/smp_processor_id.c:15
Code: 89 f6 41 55 49 89 fd 41 54 53 48 83 ec 08 e8 74 5d ec fd 65 44 8b 25 2c 5a 6e 7c 65 8b 1d c5 c6 6e 7c 81 e3 ff ff ff 7f 31 ff <89> de e8 66 5e ec fd 85 db 74 1c e8 4d 5d ec fd e8 48 5d ec fd 44
RSP: 0018:ffff88817607e2f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000040000 RBX: 0000000000000001 RCX: ffffc9000fe62000
RDX: 0000000000040000 RSI: ffffffff839326fc RDI: 0000000000000000
RBP: ffff88817607e328 R08: ffff8881b453c240 R09: ffffed103b5c5b5f
R10: ffffed103b5c5b5f R11: ffff8881dae2dafb R12: 0000000000000000
R13: ffffffff8860d160 R14: ffffffff8860d120 R15: ffff88817607e4c0
 debug_smp_processor_id+0x1c/0x20 lib/smp_processor_id.c:56
 rcu_dynticks_curr_cpu_in_eqs+0x69/0x170 kernel/rcu/tree.c:290
 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:906
 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:277
 xa_entry include/linux/xarray.h:848 [inline]
 xas_descend+0x413/0x510 lib/xarray.c:198
 xas_load+0x145/0x1e0 lib/xarray.c:234
 find_get_entry+0x3ca/0x1120 mm/filemap.c:1415
 pagecache_get_page+0x12f/0xf00 mm/filemap.c:1518
 find_get_page_flags include/linux/pagemap.h:278 [inline]
 __find_get_block_slow fs/buffer.c:205 [inline]
 __find_get_block+0x63a/0xf20 fs/buffer.c:1294
 __getblk_slow fs/buffer.c:1039 [inline]
 __getblk_gfp+0x2b3/0xd50 fs/buffer.c:1320
 __getblk include/linux/buffer_head.h:380 [inline]
 __breadahead+0x8c/0x160 fs/buffer.c:1330
 sb_breadahead include/linux/buffer_head.h:319 [inline]
 fat_dir_readahead fs/fat/dir.c:66 [inline]
 fat__get_entry+0x4d4/0xa40 fs/fat/dir.c:99
 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: 0033:0x457659
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:00007ff59b7e9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457659
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff59b7ea6d4
R13: 00000000004bdcef R14: 00000000004cd010 R15: 00000000ffffffff
sched: RT throttling activated