rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (2 GPs behind) idle=8d54/0/0x1 softirq=17251/17255 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=11257, q=877 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.14.0-syzkaller-05877-g1a9239bb4253 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d d4 9c b2 0c 48 89 de 5b e9 13 bf 5c 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 10 61 93 65 8b 15 18 99 9d 11 81 e2 00 01 ff 00 RSP: 0018:ffffc90000007c08 EFLAGS: 00000002 RAX: ffffffff8a18337f RBX: ffff888027438000 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888027438080 RBP: 0000000000000000 R08: ffff888027438083 R09: 1ffff11004e87010 R10: dffffc0000000000 R11: ffffed1004e87011 R12: 0000000000000000 R13: ffff888027438000 R14: ffff888027438080 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812500f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fcc0006950 CR3: 00000000759b4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: taprio_set_budgets+0x25f/0x380 net/sched/sch_taprio.c:664 advance_sched+0x98d/0xca0 net/sched/sch_taprio.c:977 __run_hrtimer kernel/time/hrtimer.c:1791 [inline] __hrtimer_run_queues+0x5a6/0xd40 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 61 93 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 95 f7 89 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:ffffffff8ea07ca8 EFLAGS: 00000246 RAX: ffffffff8ea96580 RBX: ffff888020aa2864 RCX: ffffffff8c2077ac RDX: 0000000000000001 RSI: ffff888020aa2800 RDI: ffff888020aa2864 RBP: ffffffff93626c78 R08: ffff8880b8632b5b R09: 1ffff110170c656b R10: dffffc0000000000 R11: ffffffff8c209280 R12: ffff88801ef96000 R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff8f53a260 acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:701 cpuidle_enter_state+0x111/0x480 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 rest_init+0x2dc/0x300 init/main.c:743 start_kernel+0x484/0x510 init/main.c:1099 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494 common_startup_64+0x13e/0x147 rcu: rcu_preempt kthread starved for 10498 jiffies! g11257 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:26544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5366 [inline] __schedule+0x1b18/0x50e0 kernel/sched/core.c:6747 __schedule_loop kernel/sched/core.c:6824 [inline] schedule+0x163/0x360 kernel/sched/core.c:6839 schedule_timeout+0x15b/0x290 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+0x7a9/0x920 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: 1 UID: 0 PID: 68 Comm: kworker/u8:4 Not tainted 6.14.0-syzkaller-05877-g1a9239bb4253 #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:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bba/0x2d40 kernel/smp.c:885 Code: 01 31 ff e8 a8 02 0c 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 58 fe 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df 0f b6 04 03 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 33 fe 0b 00 eb db 44 RSP: 0000:ffffc9000157f640 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170c820d RCX: ffff88801cb61e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000157f840 R08: ffffffff81b77898 R09: 1ffffffff20ba64e R10: dffffc0000000000 R11: fffffbfff20ba64f R12: ffff8880b873ad08 R13: ffff8880b8641068 R14: ffff8880b873ad00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812510f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0720b25dc3 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 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