rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=5e4c/0/0x1 softirq=18825/18826 fqs=4 rcu: (detected by 0, t=10502 jiffies, g=12817, q=217 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.14.0-syzkaller-12456-gacc4d5ff0b61 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:debug_object_deactivate+0x0/0x390 lib/debugobjects.c:862 Code: 89 ee e8 a3 a6 34 00 e9 02 ff ff ff 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 RSP: 0018:ffffc90000a08d18 EFLAGS: 00000006 RAX: ffffffff81b0bbec RBX: ffff88802df1c340 RCX: ffff88801d6eda00 RDX: 0000000000010000 RSI: ffffffff8c4cd980 RDI: ffff88802df1c340 RBP: ffffc90000a08ea0 R08: ffffffff81b0881f R09: 0000000000000000 R10: ffff88807ec94348 R11: ffffed100fd9286b R12: 1ffff110170e4f03 R13: dffffc0000000000 R14: ffff88802df1c340 R15: ffff8880b87277c0 FS: 0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4916a55d58 CR3: 0000000030410000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline] debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:492 __run_hrtimer kernel/time/hrtimer.c:1759 [inline] __hrtimer_run_queues+0x310/0xd40 kernel/time/hrtimer.c:1855 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1917 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 08 10 65 93 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 15 6d 82 00 f3 0f 1e fa fb f4 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197d08 EFLAGS: 00000246 RAX: ffff88801d6eda00 RBX: ffff8880216fc064 RCX: ffffffff8c27e8fc RDX: 0000000000000001 RSI: ffff8880216fc000 RDI: ffff8880216fc064 RBP: ffffffff93666af8 R08: ffff8880b8732b5b R09: 1ffff110170e656b R10: dffffc0000000000 R11: ffffffff8c2803e0 R12: ffff888021b68000 R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff8f53a080 acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:701 cpuidle_enter_state+0x111/0x490 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:389 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x374/0x5d0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 start_secondary+0xfe/0x100 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147 rcu: rcu_preempt kthread starved for 10494 jiffies! g12817 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:26952 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 970 Comm: kworker/u8:5 Not tainted 6.14.0-syzkaller-12456-gacc4d5ff0b61 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217 Code: 08 10 65 93 65 8b 15 38 ca a1 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 <83> fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c RSP: 0018:ffffc90003a37638 EFLAGS: 00000246 RAX: ffffffff81b7679d RBX: 1ffff110170e7e61 RCX: ffff888026295a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003a37840 R08: ffffffff81b76768 R09: 1ffffffff20bd2ce R10: dffffc0000000000 R11: fffffbfff20bd2cf R12: ffff8880b863ab88 R13: ffff8880b873f308 R14: ffff8880b863ab80 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124fcf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000600 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0x1bcd/0x2d40 kernel/smp.c:885 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2455 [inline] text_poke_bp_batch+0x354/0xb30 arch/x86/kernel/alternative.c:2665 text_poke_flush arch/x86/kernel/alternative.c:2856 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xc0/0x250 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245