rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P10949/1:b..l
	(detected by 1, t=10502 jiffies, g=46777, q=92)
task:syz.1.1572      state:R  running task     stack:22480 pid:10949 ppid:  4188 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6596
 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:404 [inline]
 filemap_map_pages+0x10a5/0x1450 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+0x25bb/0x4440 mm/memory.c:4883
 faultin_page mm/gup.c:976 [inline]
 __get_user_pages+0x952/0x11e0 mm/gup.c:1197
 __get_user_pages_locked mm/gup.c:1382 [inline]
 get_dump_page+0x18c/0x670 mm/gup.c:1838
 dump_user_range+0x54/0x340 fs/coredump.c:1013
 elf_core_dump+0x2fe0/0x3530 fs/binfmt_elf.c:2285
 do_coredump+0x14e8/0x2a40 fs/coredump.c:894
 get_signal+0x531/0x12e0 kernel/signal.c:2895
 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1499
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fbeffd73bd7
RSP: 002b:00007fbefe0d6120 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fbeffebe159
RDX: 00007fbefe0d6140 RSI: 00007fbefe0d6270 RDI: 000000000000000b
RBP: 00007fbefff55024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fbf00146128 R14: 00007fbf00146090 R15: 00007ffc99491fa8
 </TASK>
rcu: rcu_preempt kthread starved for 9621 jiffies! g46777 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:27792 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
 kthread+0x42e/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 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729