rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5892/1:b..l P4015/1:b..l (detected by 0, t=10502 jiffies, g=11961, q=540) task:syz-executor.4 state:R running task stack: 0 pid: 4015 ppid: 3997 flags:0x00000004 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5026 [inline] __schedule+0xf10/0x1e38 kernel/sched/core.c:6372 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6776 arm64_preempt_schedule_irq+0x174/0x2c4 arch/arm64/kernel/entry-common.c:260 el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:451 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:458 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:580 lock_is_held_type+0x15c/0x1a8 kernel/locking/lockdep.c:5670 lock_is_held include/linux/lockdep.h:287 [inline] task_css include/linux/cgroup.h:495 [inline] mem_cgroup_from_task+0x70/0x118 mm/memcontrol.c:935 get_mem_cgroup_from_mm+0xd4/0x3dc mm/memcontrol.c:988 __mem_cgroup_charge+0x24/0xa8 mm/memcontrol.c:6776 mem_cgroup_charge include/linux/memcontrol.h:700 [inline] wp_page_copy+0x244/0x132c mm/memory.c:3048 do_wp_page+0x6c4/0x9c4 handle_pte_fault mm/memory.c:4639 [inline] __handle_mm_fault mm/memory.c:4756 [inline] handle_mm_fault+0x1ce4/0x33c4 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_mem_abort+0x70/0x1d8 arch/arm64/mm/fault.c:819 el0_da+0x94/0x20c arch/arm64/kernel/entry-common.c:482 el0t_64_sync_handler+0xc0/0xe4 arch/arm64/kernel/entry-common.c:617 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 task:syz-executor.5 state:R running task stack: 0 pid: 5892 ppid: 4003 flags:0x00000004 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5026 [inline] __schedule+0xf10/0x1e38 kernel/sched/core.c:6372 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6776 arm64_preempt_schedule_irq+0x174/0x2c4 arch/arm64/kernel/entry-common.c:260 el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:451 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:458 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:580 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] count_memcg_events include/linux/memcontrol.h:1058 [inline] count_memcg_event_mm+0x1d0/0x308 include/linux/memcontrol.h:1081 handle_mm_fault+0x1c8/0x33c4 mm/memory.c:4834 __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:482 el0t_64_sync_handler+0xc0/0xe4 arch/arm64/kernel/entry-common.c:617 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 rcu: rcu_preempt kthread starved for 9768 jiffies! g11961 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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: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:5026 [inline] __schedule+0xf10/0x1e38 kernel/sched/core.c:6372 preempt_schedule_common+0x140/0x260 kernel/sched/core.c:6548 preempt_schedule+0x64/0x84 kernel/sched/core.c:6573 __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+0x228/0x12cc kernel/rcu/tree.c:1959 rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2132 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 0: task:syz-executor.3 state:R running task stack: 0 pid: 5891 ppid: 4019 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:8636 dump_cpu_task+0x84/0xa8 kernel/sched/core.c:10908 rcu_check_gp_kthread_starvation+0x1f0/0x254 kernel/rcu/tree_stall.h:482 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3911 [inline] rcu_sched_clock_irq+0x43bc/0x4904 kernel/rcu/tree.c:2606 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+0x4e0/0xb64 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:442 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:458 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:580 arch_local_irq_enable arch/arm64/include/asm/irqflags.h:35 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0xa4/0x134 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:413 [inline] get_signal+0x11b4/0x1550 kernel/signal.c:2892 do_signal arch/arm64/kernel/signal.c:890 [inline] do_notify_resume+0x320/0x32b8 arch/arm64/kernel/signal.c:943 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:597 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584