rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=e424/1/0x4000000000000000 softirq=75807/75808 fqs=5091 rcu: hardirqs softirqs csw/system rcu: number: 1323060 0 0 rcu: cputime: 19068 33411 65 ==> 52510(ms) rcu: (t=10503 jiffies g=99921 q=887 ncpus=2) rcu: rcu_preempt kthread timer wakeup didn't happen for 304 jiffies! g99921 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=67314 rcu: rcu_preempt kthread starved for 307 jiffies! g99921 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26568 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148 Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 bb 40 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56 RSP: 0018:ffffc900001f07f8 EFLAGS: 00000246 RAX: ffffffff813a13aa RBX: 0000000000000003 RCX: ffff88801b26bc00 RDX: 0000000000000100 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80 RBP: ffffc900001f08d0 R08: ffffffff90d945ef R09: 1ffffffff21b28bd R10: dffffc0000000000 R11: fffffbfff21b28be R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff9200003e104 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5829515000 CR3: 000000007bf0e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] kvm_wait+0x22f/0x290 arch/x86/kernel/kvm.c:1058 pv_wait arch/x86/include/asm/paravirt.h:598 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x61a/0x9d0 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:356 [inline] send_hsr_supervision_frame+0x311/0xb90 net/hsr/hsr_device.c:323 hsr_announce+0x192/0x340 net/hsr/hsr_device.c:402 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148 Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 bb 40 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c2 RAX: 602e44087ecd7c00 RBX: ffffffff8161881b RCX: 602e44087ecd7c00 RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80 RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65 R10: dffffc0000000000 R11: ffffed10171e6d66 R12: ffffffff8e4a2128 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100364d780 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1eb/0x510 kernel/sched/idle.c:282 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b CPU: 0 PID: 15836 Comm: syz.5.2447 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 0a d9 1a f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e2 53 ea f6 65 8b 05 d3 9a 92 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90000006d60 EFLAGS: 00000206 RAX: 261036773d9e7700 RBX: 0000000000000a06 RCX: 261036773d9e7700 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001 RBP: ffffc90000006de8 R08: ffffffff90d945ef R09: 1ffffffff21b28bd R10: dffffc0000000000 R11: fffffbfff21b28be R12: dffffc0000000000 R13: ffff88803039aa00 R14: ffff8880b8e3d790 R15: 1ffff92000000dac FS: 00007fef076eb6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e223ffc CR3: 000000004e04a000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] rps_unlock_irq_restore net/core/dev.c:241 [inline] enqueue_to_backlog+0xa08/0xe30 net/core/dev.c:4864 netif_rx_internal+0x119/0x4e0 net/core/dev.c:5138 __netif_rx+0x78/0xc0 net/core/dev.c:5158 veth_forward_skb drivers/net/veth.c:321 [inline] veth_xmit+0x550/0x9f0 drivers/net/veth.c:374 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3619 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635 __dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425 dev_queue_xmit include/linux/netdevice.h:3113 [inline] hsr_xmit net/hsr/hsr_forward.c:380 [inline] hsr_forward_do net/hsr/hsr_forward.c:471 [inline] hsr_forward_skb+0x1317/0x2120 net/hsr/hsr_forward.c:624 hsr_dev_xmit+0x1e7/0x350 net/hsr/hsr_device.c:238 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3619 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635 __dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425 neigh_output include/net/neighbour.h:543 [inline] ip6_finish_output2+0xe2e/0x1650 net/ipv6/ip6_output.c:141 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:generic_exec_single+0x476/0x4f0 kernel/smp.c:418 Code: 75 11 e8 cd e6 0a 00 48 85 db 75 16 e8 c3 e6 0a 00 eb 15 e8 bc e6 0a 00 e8 47 cd ec 08 48 85 db 74 ea e8 ad e6 0a 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c RSP: 0018:ffffc9000b84fa00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc9000d4de000 RSI: 0000000000002c38 RDI: 0000000000002c39 RBP: ffffc9000b84fad0 R08: ffffffff90d945ff R09: 1ffffffff21b28bf R10: dffffc0000000000 R11: fffffbfff21b28c0 R12: 1ffff92001709f44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92001709f65 smp_call_function_single+0x352/0x580 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x591/0x8e0 kernel/events/core.c:2948 __do_sys_perf_event_open kernel/events/core.c:12915 [inline] __se_sys_perf_event_open+0x17fa/0x1c20 kernel/events/core.c:12567 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fef0678f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fef076eb038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fef069e5fa0 RCX: 00007fef0678f749 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007fef06813f91 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef069e6038 R14: 00007fef069e5fa0 R15: 00007ffd09c37d78