syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P21356/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=167125, q=191 ncpus=2)
task:syz-executor.4  state:R  running task     stack:24016 pid:21356 tgid:21334 ppid:17660  flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0x1796/0x49d0 kernel/sched/core.c:6745
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x13b/0x190
Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9000b7ef078 EFLAGS: 00000206
RAX: 2da9589efd244200 RBX: 0000000000000000 RCX: ffff888023705a00
RDX: ffff888023705a00 RSI: ffffffff8bcacd00 RDI: ffffffff8c1f2480
RBP: 0000000000000002 R08: ffffffff8b78f7f7 R09: 1ffffffff25ee8b0
R10: dffffc0000000000 R11: fffffbfff25ee8b1 R12: 0000000000000246
R13: ffff888023705a00 R14: 00000000ffffffff R15: ffff88807a275a68
 lock_is_held include/linux/lockdep.h:231 [inline]
 xa_entry include/linux/xarray.h:1220 [inline]
 xas_descend lib/xarray.c:207 [inline]
 xas_load+0x19c/0x5c0 lib/xarray.c:245
 xa_load+0x1fc/0x350 lib/xarray.c:1477
 page_cache_ra_unbounded+0x15d/0x7f0 mm/readahead.c:230
 do_async_mmap_readahead mm/filemap.c:3203 [inline]
 filemap_fault+0x78d/0x1760 mm/filemap.c:3299
 f2fs_filemap_fault+0xa3/0x2e0 fs/f2fs/file.c:45
 __do_fault+0x135/0x460 mm/memory.c:4562
 do_read_fault mm/memory.c:4926 [inline]
 do_fault mm/memory.c:5056 [inline]
 do_pte_missing mm/memory.c:3903 [inline]
 handle_pte_fault+0x3d8d/0x7130 mm/memory.c:5380
 __handle_mm_fault mm/memory.c:5523 [inline]
 handle_mm_fault+0xfb0/0x19d0 mm/memory.c:5688
 faultin_page mm/gup.c:1290 [inline]
 __get_user_pages+0x6ef/0x1590 mm/gup.c:1589
 populate_vma_page_range+0x264/0x330 mm/gup.c:2029
 __mm_populate+0x27a/0x460 mm/gup.c:2132
 mm_populate include/linux/mm.h:3464 [inline]
 vm_mmap_pgoff+0x2c3/0x3d0 mm/util.c:578
 ksys_mmap_pgoff+0x4f1/0x720 mm/mmap.c:1443
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb39147cea9
RSP: 002b:00007fb39220d0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fb3915b4050 RCX: 00007fb39147cea9
RDX: 8088e3ad122bc192 RSI: 0000000000600000 RDI: 0000000020000000
RBP: 00007fb3914ebff4 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000004002011 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb3915b4050 R15: 00007ffcb2903078
 </TASK>
rcu: rcu_preempt kthread starved for 10531 jiffies! g167125 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:24464 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0x1796/0x49d0 kernel/sched/core.c:6745
 __schedule_loop kernel/sched/core.c:6822 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6837
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112