rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9401/1:b..l
	(detected by 0, t=10502 jiffies, g=28185, q=63)
task:syz.3.1274      state:R  running task     stack:27840 pid: 9401 ppid:  4171 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6552
 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6577
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:403 [inline]
 filemap_map_pages+0x1031/0x1390 mm/filemap.c:3353
 do_fault_around mm/memory.c:4243 [inline]
 do_read_fault mm/memory.c:4258 [inline]
 do_fault mm/memory.c:4392 [inline]
 handle_pte_fault mm/memory.c:4650 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x2580/0x43c0 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f13b001cc8d
RSP: 002b:00007ffef73d2620 EFLAGS: 00010202
RAX: 000000110c328000 RBX: 00007f13b0e93720 RCX: 0000000000000007
RDX: 00000000000018fa RSI: 0000000000000de3 RDI: 0000000000000080
RBP: ffffffff886378fa R08: 00007f13b0364038 R09: 00007f13b0350000
R10: 00007f13af7ad008 R11: 000000000000000c R12: 000000000000000c
R13: 0000000000000000 R14: ffffffff88637f92 R15: 0000000000000095
 </TASK>
rcu: rcu_preempt kthread starved for 10391 jiffies! g28185 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27848 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:722