rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=87b/0/0x1 softirq=23363/23373 fqs=0 (t=10501 jiffies g=31557 q=338) rcu: rcu_preempt kthread starved for 10502 jiffies! g31557 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:26680 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8000 Comm: syz.7.684 Not tainted 5.15.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:135 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:344 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:895 [inline] RIP: 0010:trace_x86_fpu_regs_activated arch/x86/include/asm/trace/fpu.h:57 [inline] RIP: 0010:fpregs_activate+0x5e/0x1c0 arch/x86/include/asm/fpu/internal.h:451 Code: 77 63 e8 75 61 51 00 89 d8 c1 e8 06 48 8d 3c c5 e8 69 e9 8d be 08 00 00 00 e8 2e 3b 9b 00 89 d8 31 db 48 0f a3 05 9a 57 ba 0c <40> 0f 92 c5 0f 92 c3 bf 02 00 00 00 89 de e8 9f 63 51 00 31 ff 89 RSP: 0018:ffffc90002e87c48 EFLAGS: 00000247 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff812f1242 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8de969e8 RBP: 0000000000000007 R08: dffffc0000000000 R09: fffffbfff1bd2d3e R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff88802a96b700 R14: ffff88802a96b700 R15: ffff88802a969dc0 FS: 000055558077c500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020029000 CR3: 000000006333e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fpregs_mark_activate arch/x86/kernel/fpu/core.c:429 [inline] fpu__clear_user_states+0x184/0x260 arch/x86/kernel/fpu/core.c:387 handle_signal arch/x86/kernel/signal.c:840 [inline] arch_do_signal_or_restart+0x1488/0x1890 arch/x86/kernel/signal.c:869 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc6916b8a50 Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 1a d0 06 00 e8 45 92 f8 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48 RSP: 002b:00007fff8756b338 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fff8756ba20 RCX: 00007fc691690819 RDX: 00007fff8756b340 RSI: 00007fff8756b470 RDI: 0000000000000021 RBP: 00007fc69184808c R08: 0000000000000010 R09: 00007fff8756bbef R10: 00007fff8756ba00 R11: 0000000000000246 R12: 0000000000064dcc R13: 00007fff8756ba00 R14: 0000000000000032 R15: 0000000000064d9a NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.15.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x320/0x600 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0x8d9/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562 Code: 79 42 f7 48 83 e3 08 0f 85 0a 01 00 00 4c 8d 74 24 20 e8 24 f4 48 f7 0f 1f 44 00 00 e8 ca 75 42 f7 0f 00 2d 63 43 a5 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 6b 4e 8c f7 RSP: 0018:ffffc90000d67b00 EFLAGS: 000002d3 RAX: ffffffff8a3dfdd6 RBX: 0000000000000000 RCX: ffff888017df0000 RDX: 0000000000000000 RSI: ffffffff8a8b2a80 RDI: ffffffff8ad90540 RBP: ffffc90000d67b90 R08: ffffffff8186f220 R09: ffffed1002fbe001 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001acf60 R13: ffff88801ea54004 R14: ffffc90000d67b20 R15: dffffc0000000000 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:697 cpuidle_enter_state+0x521/0xef0 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3e4/0x670 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x371/0x500 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb