rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=467/1/0x4000000000000002 softirq=7907/7907 fqs=2 (t=10501 jiffies g=6925 q=555) rcu: rcu_preempt kthread starved for 10497 jiffies! g6925 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: 0 pid: 15 ppid: 2 flags:0x00000008 Call trace: __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:521 context_switch kernel/sched/core.c:5049 [inline] __schedule+0xe08/0x1bf8 kernel/sched/core.c:6395 schedule+0x11c/0x1c8 kernel/sched/core.c:6478 schedule_timeout+0x180/0x2c8 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x25c/0x11f0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xc4/0x2a8 kernel/rcu/tree.c:2145 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:856 rcu: Stack dump where RCU GP kthread last ran: Task dump for CPU 1: task:syz.4.20 state:R running task stack: 0 pid: 5124 ppid: 4834 flags:0x00000000 Call trace: __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:521 .str.2+0xad21b5/0xc4b610 Task dump for CPU 0: task:syz.3.25 state:R running task stack: 0 pid: 5122 ppid: 4822 flags:0x00000001 Call trace: dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 sched_show_task+0x3c8/0x4b4 kernel/sched/core.c:8659 dump_cpu_task+0x84/0xa8 kernel/sched/core.c:10946 rcu_dump_cpu_stacks+0x2bc/0x4b0 kernel/rcu/tree_stall.h:350 print_cpu_stall+0x4e8/0xa74 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0xbb4/0x1810 kernel/rcu/tree.c:2619 update_process_times+0x1c4/0x260 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x30c/0x4bc kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x3fc/0xb6c kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x2bc/0xb5c 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/0x76c kernel/irq/chip.c:930 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq_desc kernel/irq/irqdesc.c:652 [inline] handle_domain_irq+0x144/0x1fc kernel/irq/irqdesc.c:707 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:903 do_interrupt_handler+0x6c/0x88 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:522 get_current arch/arm64/include/asm/current.h:19 [inline] __sanitizer_cov_trace_pc+0x28/0xac kernel/kcov.c:205 check_preemption_disabled+0x28/0x164 lib/smp_processor_id.c:14 debug_smp_processor_id+0x20/0x2c lib/smp_processor_id.c:60 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline] rcu_is_watching+0x50/0x134 kernel/rcu/tree.c:1123 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0xc4/0x620 kernel/locking/lockdep.c:5594 __might_fault+0xc8/0x128 mm/memory.c:5357 restore_sigframe arch/arm64/kernel/signal.c:506 [inline] __arm64_sys_rt_sigreturn+0x298/0x1fec arch/arm64/kernel/signal.c:558 __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+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584