rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=d53c/1/0x4000000000000002 softirq=59859/59860 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=69705, q=362 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:hrtimer_set_expires include/linux/hrtimer.h:81 [inline] RIP: 0010:advance_sched+0x6b3/0xd20 net/sched/sch_taprio.c:990 Code: 00 0f 85 d8 05 00 00 48 8b 1c 24 48 8b 7c 24 40 4c 89 7b e8 e8 ce f5 f6 01 48 8d 7b 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa <48> c1 ea 03 80 3c 02 00 0f 85 b6 05 00 00 48 8b 04 24 48 8d 78 40 RSP: 0018:ffffc90000007de8 EFLAGS: 00000082 RAX: dffffc0000000000 RBX: ffff88801ef8a300 RCX: 0000000000000000 RDX: ffff88801ef8a328 RSI: 0000000000000004 RDI: ffff88801ef8a328 RBP: ffff8880575a6800 R08: 0000000000000000 R09: ffffed1003df1455 R10: ffff88801ef8a2ab R11: 0000000000000000 R12: 0000000000000000 R13: 4a65b2238cdd2455 R14: ffff8880575a6c00 R15: ffff8880575a6c00 FS: 0000000000000000(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b343fdff8 CR3: 000000002d9b4000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:sched_core_balance+0xa6/0xff0 kernel/sched/core.c:6535 Code: 0e 00 e8 2d bb e3 09 5a 85 c0 0f 85 3d 0b 00 00 e9 02 0a 00 00 49 8d 7c 24 48 e8 85 b0 e6 09 e8 40 bb 3b 00 fb 48 63 44 24 58 <48> c7 c3 c0 f4 64 94 48 89 dd 48 89 44 24 08 48 83 f8 08 0f 83 6c RSP: 0018:ffffffff8e807b78 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffffff8e891480 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e1a9419 RDI: ffffffff8c400480 RBP: ffffffff8e807c98 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880b843b4c0 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8880b843b4c0 do_balance_callbacks kernel/sched/core.c:5134 [inline] __balance_callbacks kernel/sched/core.c:5190 [inline] finish_lock_switch kernel/sched/core.c:5239 [inline] finish_task_switch.isra.0+0x538/0x10c0 kernel/sched/core.c:5359 context_switch kernel/sched/core.c:5513 [inline] __schedule+0x1264/0x6730 kernel/sched/core.c:7234 schedule_idle+0x54/0x80 kernel/sched/core.c:7352 do_idle+0x35e/0x5b0 kernel/sched/idle.c:384 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x251/0x260 init/main.c:717 start_kernel+0x48e/0x490 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158 rcu: rcu_preempt kthread starved for 10462 jiffies! g69705 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:28656 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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: 11740 Comm: syz.1.1413 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x5a0/0x1870 kernel/smp.c:912 Code: 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 c4 9b 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 a8 10 00 00 <8b> 45 08 31 ff 83 e0 01 41 89 c6 89 c6 e8 0e 96 0c 00 45 85 f6 75 RSP: 0018:ffffc90003e7f9e8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fdd7e2 RDX: ffff88802899ca80 RSI: ffffffff81fdd7bc RDI: ffff88802899ca80 RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880 FS: 000055556bb42500(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa18fc55fd0 CR3: 000000005a1c7000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000002d DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1077 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline] smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x37a/0x550 kernel/jump_label.c:910 __static_key_slow_dec_cpuslocked.part.0+0xc5/0xf0 kernel/jump_label.c:315 __static_key_slow_dec_cpuslocked kernel/jump_label.c:297 [inline] __static_key_slow_dec kernel/jump_label.c:321 [inline] static_key_slow_dec+0x7c/0xc0 kernel/jump_label.c:336 kvm_destroy_vm virt/kvm/kvm_main.c:1307 [inline] kvm_put_kvm+0x974/0xc10 virt/kvm/kvm_main.c:1331 kvm_vm_release+0x3c/0x50 virt/kvm/kvm_main.c:1354 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f577799e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdb077a638 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f5777c27da0 RCX: 00007f577799e0d9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f5777c27da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f5777c27cb0 R11: 0000000000000246 R12: 0000000000089547 R13: 00007f5777c2627c R14: 00000000000894e2 R15: 00007ffdb077a740