rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14281/1:b..l (detected by 1, t=10502 jiffies, g=43237, q=134) task:syz-executor.2 state:R running task stack: 0 pid:14281 ppid: 4010 flags:0x00000004 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_common+0x140/0x260 kernel/sched/core.c:6552 preempt_schedule+0x64/0x84 kernel/sched/core.c:6577 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0xe4/0x128 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:403 [inline] filemap_map_pages+0xc10/0xd54 mm/filemap.c:3344 do_fault_around mm/memory.c:4213 [inline] do_read_fault mm/memory.c:4228 [inline] do_fault mm/memory.c:4362 [inline] handle_pte_fault mm/memory.c:4621 [inline] __handle_mm_fault mm/memory.c:4756 [inline] handle_mm_fault+0x213c/0x33c4 mm/memory.c:4854 __do_page_fault arch/arm64/mm/fault.c:505 [inline] do_page_fault+0x700/0xb60 arch/arm64/mm/fault.c:605 do_translation_fault+0xe8/0x138 arch/arm64/mm/fault.c:686 do_mem_abort+0x70/0x1d8 arch/arm64/mm/fault.c:819 el0_da+0x94/0x20c arch/arm64/kernel/entry-common.c:494 el0t_64_sync_handler+0xc0/0xe4 arch/arm64/kernel/entry-common.c:629 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 rcu: rcu_preempt kthread starved for 10502 jiffies! g43237 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack: 0 pid: 15 ppid: 2 flags:0x00000008 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_common+0x140/0x260 kernel/sched/core.c:6552 preempt_schedule+0x64/0x84 kernel/sched/core.c:6577 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x114/0x158 kernel/locking/spinlock.c:194 prepare_to_swait_event+0x2a0/0x2ec kernel/sched/swait.c:120 rcu_gp_fqs_loop+0x238/0x13d4 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2145 kthread+0x37c/0x45c kernel/kthread.c:319 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 rcu: Stack dump where RCU GP kthread last ran: Task dump for CPU 1: task:syz-executor.0 state:R running task stack: 0 pid:14280 ppid: 4008 flags:0x00000001 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 sched_show_task+0x43c/0x574 kernel/sched/core.c:8640 dump_cpu_task+0x84/0xa8 kernel/sched/core.c:10914 rcu_check_gp_kthread_starvation+0x1f0/0x254 kernel/rcu/tree_stall.h:488 print_other_cpu_stall+0x202c/0x2290 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0x1894/0x1b8c kernel/rcu/tree.c:2619 update_process_times+0x1d4/0x270 kernel/time/timer.c:1788 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x340/0x4f8 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x458/0xca4 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x2c0/0xb64 kernel/time/hrtimer.c:1811 timer_handler drivers/clocksource/arm_arch_timer.c:659 [inline] arch_timer_handler_virt+0x74/0x88 drivers/clocksource/arm_arch_timer.c:670 handle_percpu_devid_irq+0x29c/0x7fc kernel/irq/chip.c:933 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq_desc kernel/irq/irqdesc.c:651 [inline] handle_domain_irq+0xec/0x178 kernel/irq/irqdesc.c:706 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:758 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x74/0x94 arch/arm64/kernel/entry-common.c:267 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:580 __sanitizer_cov_trace_const_cmp8+0x1c/0xa8 kernel/kcov.c:292 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584