rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=271c/1/0x4000000000000000 softirq=73061/73061 fqs=108 rcu: (detected by 0, t=10502 jiffies, g=74817, q=723 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 15182 Comm: syz.7.2418 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] RIP: 0010:do_raw_spin_lock+0x79/0x260 kernel/locking/spinlock_debug.c:115 Code: c7 42 04 04 f3 f3 f3 65 48 8b 15 aa bc 7d 12 48 89 54 24 60 31 d2 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 <38> d0 7c 08 84 d2 0f 85 b1 01 00 00 8b 43 04 3d ad 4e ad de 0f 85 RSP: 0018:ffffc90000a08cb8 EFLAGS: 00000002 RAX: 0000000000000007 RBX: ffffffff9b94a468 RCX: d99bee890565ebb9 RDX: 0000000000000000 RSI: ffffffff8e17df68 RDI: ffffffff9b94a46c RBP: 0000000000000006 R08: 0000000041d74dc5 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff92000141198 R13: ffff88807f908300 R14: 0000000000000001 R15: 1ffff920001411b2 FS: 00007fe1535246c0(0000) GS:ffff888123ee8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000017008 CR3: 0000000074293000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:166 debug_object_activate+0x144/0x4b0 lib/debugobjects.c:873 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] enqueue_hrtimer+0x75/0x2f0 kernel/time/hrtimer.c:1109 __run_hrtimer kernel/time/hrtimer.c:2048 [inline] __hrtimer_run_queues+0x6ed/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:__vmcs_writel arch/x86/kvm/vmx/vmx_ops.h:224 [inline] RIP: 0010:vmcs_writel arch/x86/kvm/vmx/vmx_ops.h:263 [inline] RIP: 0010:vmx_set_gdt+0xd8/0x170 arch/x86/kvm/vmx/vmx.c:3792 Code: d2 0f 95 c2 40 84 d6 0f 85 89 00 00 00 83 e0 07 38 c1 0f 9e c2 84 c9 0f 95 c0 84 c2 75 78 48 8b 5b 02 b8 16 68 00 00 0f 79 c3 <76> 22 e8 51 bf 6b 00 5b 5d e9 0a 74 1e 0a e8 45 bf 6b 00 e8 50 d1 RSP: 0018:ffffc90004357ae0 EFLAGS: 00000202 RAX: 0000000000006816 RBX: 0000000000001000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffc90004357b6a RBP: 00000000000007ff R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90004357c00 R13: ffff88804b4bfd08 R14: ffffc90004357b68 R15: 0000000000000000 __set_sregs_common.constprop.0+0x5ec/0x1b60 arch/x86/kvm/x86.c:12413 __set_sregs+0x7e/0x260 arch/x86/kvm/x86.c:12464 kvm_arch_vcpu_ioctl_set_sregs+0xce/0x110 arch/x86/kvm/x86.c:12530 kvm_vcpu_ioctl+0x8ee/0x1700 virt/kvm/kvm_main.c:4533 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe15259daeb Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fe153522450 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007fe15259daeb RDX: 00007fe153522a90 RSI: 000000004138ae84 RDI: 0000000000000008 RBP: 0000200000017000 R08: 0000000000009120 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000017800 R13: 000000000000000b R14: 0000000000000003 R15: 000000000000000b rcu: rcu_preempt kthread starved for 10285 jiffies! g74817 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:27528 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: 0 UID: 0 PID: 14573 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x589/0x16c0 kernel/smp.c:892 Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 c9 95 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31 RSP: 0000:ffffc90003ac7888 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fd46fd RDX: ffff88805387ca80 RSI: ffffffff81fd46d7 RDI: ffff88805387ca80 RBP: ffff8880b8541240 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170a8249 R14: 0000000000000001 R15: ffff8880b843c880 FS: 0000555586d6d500(0000) GS:ffff888123de8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555586d88a48 CR3: 000000001efce000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451 flush_tlb_page arch/x86/include/asm/tlbflush.h:345 [inline] ptep_clear_flush+0x148/0x170 mm/pgtable-generic.c:104 wp_page_copy mm/memory.c:3941 [inline] do_wp_page+0x12a4/0x4350 mm/memory.c:4336 handle_pte_fault mm/memory.c:6395 [inline] __handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6517 handle_mm_fault+0x37b/0xa30 mm/memory.c:6686 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f39f17629e0 Code: e4 28 00 48 8d 0c 1e 49 39 d0 49 89 48 60 0f 95 c2 48 29 d8 0f b6 d2 48 83 c8 01 48 c1 e2 02 48 09 da 48 83 ca 01 48 89 56 08 <48> 89 41 08 48 8d 4e 10 eb b0 48 8d 0d a7 da 0c 00 ba 9e 10 00 00 RSP: 002b:00007ffe612cf040 EFLAGS: 00010206 RAX: 00000000000185c1 RBX: 0000000000008040 RCX: 0000555586d88a40 RDX: 0000000000008041 RSI: 0000555586d80a00 RDI: 0000000000000004 RBP: 0000000000000802 R08: 00007f39f19f0e20 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000008030 R13: 0000000000000000 R14: 00007f39f19f0e80 R15: 0000000000000000