rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5858/1:b..l rcu: (detected by 0, t=10503 jiffies, g=8409, q=6523 ncpus=2) task:kworker/1:3 state:R running task stack:25128 pid:5858 tgid:5858 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline] RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline] RIP: 0010:gc_worker+0x2d5/0x16e0 net/netfilter/nf_conntrack_core.c:1548 Code: 00 00 48 c7 c7 88 24 ac 90 e8 f7 3e e0 f7 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 85 ee 03 f8 58 48 85 db 0f 85 d4 0f 00 00 06 f3 03 f8 8b 1d a0 09 f5 06 41 89 dc 31 ff 41 83 e4 01 44 89 RSP: 0018:ffffc9000421fb58 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff89b72619 RDX: ffff8880293a1e00 RSI: ffffffff89b72628 RDI: 0000000000000007 RBP: ffffffff9b2ae86c R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000002c10 R12: ffff888025000000 R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001770 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 1069 jiffies! g8409 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:28000 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:fib6_table_lookup+0x61/0xa30 net/ipv6/route.c:2226 Code: e8 03 89 54 24 34 49 89 c5 48 8d 04 28 44 89 4c 24 30 48 c7 84 24 80 00 00 00 b3 8a b5 41 48 c7 84 24 88 00 00 00 70 e6 dd 8d <48> c7 84 24 90 00 00 00 70 eb 3f 8a c7 00 f1 f1 f1 f1 c7 40 04 01 RSP: 0018:ffffc90000007608 EFLAGS: 00000a06 RAX: fffff52000000ed1 RBX: ffffc90000007a58 RCX: ffffc90000007a58 RDX: 000000000000001e RSI: ffff8880339d0c00 RDI: ffff88807a9d4880 RBP: dffffc0000000000 R08: ffffc900000077c0 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000005ca7 R12: ffffc900000077c0 R13: 1ffff92000000ed1 R14: ffff8880339d0c00 R15: ffffc900000077c0 FS: 0000000000000000(0000) GS:ffff8881246c4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc8847db408 CR3: 0000000069842000 CR4: 00000000003526f0 Call Trace: ip6_pol_route+0x1cc/0x1230 net/ipv6/route.c:2269 pol_lookup_func include/net/ip6_fib.h:617 [inline] fib6_rule_lookup+0x536/0x720 net/ipv6/fib6_rules.c:120 ip6_route_input_lookup net/ipv6/route.c:2338 [inline] ip6_route_input+0x662/0xc00 net/ipv6/route.c:2641 ip6_rcv_finish_core.constprop.0+0x1a0/0x5d0 net/ipv6/ip6_input.c:66 ip6_rcv_finish net/ipv6/ip6_input.c:77 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ipv6_rcv+0x1e8/0x650 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5979 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092 process_backlog+0x442/0x15e0 net/core/dev.c:6444 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7494 napi_poll net/core/dev.c:7557 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7684 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 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+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 0c 65 02 c3 cc cc cc cc 0f 1f 00 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 63 81 19 00 fb f4 3c 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6 RAX: 0000000000047124 RBX: 0000000000000000 RCX: ffffffff8b908bf9 RDX: ffffed1017086656 RSI: ffffffff8c162c80 RDI: ffffffff8190cca1 RBP: fffffbfff1c52ef8 R08: 0000000000000000 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e2977c0 R14: ffffffff90ab7690 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:744 start_kernel+0x3ee/0x4d0 init/main.c:1097 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148