rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=3ad/1/0x4000000000000000 softirq=11677/11677 fqs=7 (t=10500 jiffies g=14845 q=554) rcu: rcu_preempt kthread starved for 10485 jiffies! g14845 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:28016 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 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: 5244 Comm: syz.1.27 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:208 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 7f 9a d0 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90002dbf2d0 EFLAGS: 00000046 RAX: 000000000000003e RBX: 000000000000003e RCX: 0000000000000838 RDX: 0000000000000000 RSI: 000000000000003e RDI: 0000000000000838 RBP: 000000000000003e R08: ffffffff8d8a06ef R09: 1ffffffff1b140dd R10: dffffc0000000000 R11: fffffbfff1b140de R12: ffff8880b90272c0 R13: ffff8880b90272b8 R14: ffffffff8be359d8 R15: dffffc0000000000 FS: 00007f31f4d316c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff3abbb2c45 CR3: 0000000073335000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_write arch/x86/include/asm/apic.h:395 [inline] lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:468 clockevents_program_min_delta+0x1a9/0x340 kernel/time/clockevents.c:248 hrtimer_start_range_ns+0xa9a/0xc20 kernel/time/hrtimer.c:1287 hrtimer_start include/linux/hrtimer.h:420 [inline] stimer_start arch/x86/kvm/hyperv.c:-1 [inline] kvm_hv_process_stimers+0x131a/0x1ac0 arch/x86/kvm/hyperv.c:863 vcpu_enter_guest+0x4793/0x7010 arch/x86/kvm/x86.c:9883 vcpu_run arch/x86/kvm/x86.c:10192 [inline] kvm_arch_vcpu_ioctl_run+0xdea/0x1f40 arch/x86/kvm/x86.c:10432 kvm_vcpu_ioctl+0x8f7/0xc10 virt/kvm/kvm_main.c:3894 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f31f56cdef9 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:00007f31f4d31028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f31f5938fa0 RCX: 00007f31f56cdef9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f31f5762ee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f31f5939038 R14: 00007f31f5938fa0 R15: 00007ffeec73fa08 NMI backtrace for cpu 1 CPU: 1 PID: 5238 Comm: syz.3.20 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 sched: RT throttling activated nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:2021 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 4f 9d 8b f7 65 8b 05 70 86 3b 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90002ecf380 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 8b80742c2e7d4000 RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: 0000000000000001 RBP: ffffc90002ecf410 R08: ffffffff901d820f R09: 1ffffffff203b041 R10: dffffc0000000000 R11: fffffbfff203b042 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b912a240 R15: 1ffff920005d9e70 hrtimer_start include/linux/hrtimer.h:420 [inline] stimer_start arch/x86/kvm/hyperv.c:-1 [inline] kvm_hv_process_stimers+0x131a/0x1ac0 arch/x86/kvm/hyperv.c:863 vcpu_enter_guest+0x4793/0x7010 arch/x86/kvm/x86.c:9883 vcpu_run arch/x86/kvm/x86.c:10192 [inline] kvm_arch_vcpu_ioctl_run+0xdea/0x1f40 arch/x86/kvm/x86.c:10432 kvm_vcpu_ioctl+0x8f7/0xc10 virt/kvm/kvm_main.c:3894 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff6b1d7fef9 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:00007ff6b13e3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff6b1feafa0 RCX: 00007ff6b1d7fef9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007ff6b1e14ee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff6b1feb038 R14: 00007ff6b1feafa0 R15: 00007ffcf7743908