rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (6 ticks this GP) idle=d0bc/1/0x4000000000000000 softirq=19620/19620 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5843/1:b.el P5959/1:b..l rcu: (detected by 1, t=10695 jiffies, g=13009, q=642 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5941 Comm: kworker/0:3 Not tainted 6.16.0-rc1-syzkaller-00104-g7b4ac12cc929 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_power_efficient neigh_periodic_work 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:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_acquire+0xda/0x360 kernel/locking/lockdep.c:5867 Code: 9c 92 83 b8 ec 0a 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 4c 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 48 c7 c7 55 4b 99 8d e8 e9 0d c8 09 65 ff 05 e2 ea fe 10 45 31 RSP: 0018:ffffc90000006ea0 EFLAGS: 00000046 RAX: ffff888028f09e00 RBX: 0000000000000000 RCX: 713bcd5d0cc33300 RDX: 0000000000000000 RSI: ffffffff8b68aaa2 RDI: 1ffff110170c4f5b RBP: ffffffff81ae74b2 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1f4209f R12: 0000000000000000 R13: ffff8880b8627ad8 R14: 0000000000000001 R15: 0000000000000046 FS: 0000000000000000(0000) GS:ffff888125c52000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564e3f284a08 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1765 [inline] __hrtimer_run_queues+0x602/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a3 05 22 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000007358 EFLAGS: 00000246 RAX: ffffffff8172006d RBX: 0000000000000003 RCX: ffff888028f09e00 RDX: 0000000000000100 RSI: ffffffff8d98116f RDI: ffffffff8be28300 RBP: ffffc90000007430 R08: ffffffff8fa104f7 R09: 1ffffffff1f4209e R10: dffffc0000000000 R11: fffffbfff1f4209f R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff92000000e70 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] kvm_wait+0x232/0x290 arch/x86/kernel/kvm.c:1064 pv_wait arch/x86/include/asm/paravirt.h:569 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline] __pv_queued_spin_lock_slowpath+0x7bf/0xb60 kernel/locking/qspinlock.c:325 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] queued_write_lock_slowpath+0x22c/0x260 kernel/locking/qrwlock.c:73 queued_write_lock include/asm-generic/qrwlock.h:101 [inline] do_raw_write_lock+0x1f2/0x260 kernel/locking/spinlock_debug.c:211 ___neigh_create+0xe81/0x2260 net/core/neighbour.c:641 ip6_finish_output2+0xb4d/0x16a0 net/ipv6/ip6_output.c:132 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:226 NF_HOOK include/linux/netfilter.h:317 [inline] ndisc_send_skb+0xb47/0x1400 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4041 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x286/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 neigh_periodic_work+0xb41/0xd60 net/core/neighbour.c:966 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:udevd state:R running task stack:25960 pid:5959 tgid:5959 ppid:5205 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] wp_page_copy mm/memory.c:3670 [inline] do_wp_page+0x1d1d/0x5800 mm/memory.c:4030 handle_pte_fault mm/memory.c:6105 [inline] __handle_mm_fault+0x1144/0x5620 mm/memory.c:6232 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6401 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f1133eb5db7 RSP: 002b:00007ffe03355930 EFLAGS: 00010202 RAX: 0000000000006010 RBX: 00000000000003e0 RCX: 0000564e3f282610 RDX: 0000000000006010 RSI: 0000564e3f27c600 RDI: 00007f1133ff1ac0 RBP: 00007f1133ff1ac0 R08: 00000000000003e0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000564e3f27c600 R13: 00007f1133ff1ac0 R14: 00000000000003e0 R15: 00007f1133ff1ac0 task:udevd state:R running task stack:27120 pid:5843 tgid:5843 ppid:5205 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] wp_page_copy mm/memory.c:3670 [inline] do_wp_page+0x1d1d/0x5800 mm/memory.c:4030 handle_pte_fault mm/memory.c:6105 [inline] __handle_mm_fault+0x1144/0x5620 mm/memory.c:6232 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6401 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f1133eb5b69 RSP: 002b:00007ffe03355930 EFLAGS: 00010206 RAX: 00007f1133ff20e0 RBX: 0000564e3f2a60c0 RCX: 0000564e3f2a60c0 RDX: 0000564e3f2a60c0 RSI: 00007f1133ff20e0 RDI: 0000564e3f2a60c0 RBP: 00007f1133ff1ac0 R08: 0000000000002760 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000032b0 R13: 0000564e3f2a9370 R14: 00000000000001d0 R15: 00007f1133ff1ac0 rcu: rcu_preempt kthread starved for 10695 jiffies! g13009 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245