rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5886/1:b..l rcu: (detected by 1, t=10502 jiffies, g=28189, q=638 ncpus=2) task:kworker/1:4 state:R running task stack:25384 pid:5886 tgid:5886 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 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:344 [inline] RIP: 0010:gc_worker+0x2d5/0x16e0 net/netfilter/nf_conntrack_core.c:1551 Code: 00 00 48 c7 c7 88 ef a9 90 e8 77 15 ed f7 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 25 76 10 f8 58 48 85 db 0f 85 d4 0f 00 00 a6 7a 10 f8 8b 1d b0 81 fe 06 41 89 dc 31 ff 41 83 e4 01 44 89 RSP: 0018:ffffc900043efb58 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff89ab7909 RDX: ffff88807cf98000 RSI: ffffffff89ab7918 RDI: 0000000000000007 RBP: ffffffff9b26fa8c R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888031c00000 R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001715 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 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 8769 jiffies! g28189 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:27672 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc7-syzkaller-00034-g25fae0b93d1d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_preemption_disabled+0x25/0xe0 lib/smp_processor_id.c:56 Code: 90 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 05 6c 49 08 65 8b 05 fa 6b 49 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d <41> 5c e9 14 df 02 00 9c 58 f6 c4 02 74 ea 48 89 fd 65 48 8b 05 ba RSP: 0018:ffffc90000006e40 EFLAGS: 00000296 RAX: 0000000000000000 RBX: ffff888076ace480 RCX: ffffffff8a09ec43 RDX: 0000000000000001 RSI: ffffffff8c1573e0 RDI: ffffffff8c157420 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90000007388 R13: ffff888076ace497 R14: 0000000000000001 R15: ffff88807a178400 FS: 0000000000000000(0000) GS:ffff888124720000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000037d030 CR3: 0000000023aa5000 CR4: 00000000003526f0 Call Trace: rcu_lockdep_current_cpu_online+0x35/0x150 kernel/rcu/tree.c:3998 rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_held+0x27/0x50 kernel/rcu/update.c:349 ip_ignore_linkdown include/linux/inetdevice.h:270 [inline] fib_lookup_good_nhc+0x2f6/0x3f0 net/ipv4/fib_trie.c:1408 fib_table_lookup+0xd03/0x2300 net/ipv4/fib_trie.c:1594 fib4_rule_action net/ipv4/fib_rules.c:138 [inline] fib4_rule_action+0x1f5/0x3c0 net/ipv4/fib_rules.c:110 fib_rules_lookup+0xe16/0x1030 net/core/fib_rules.c:339 __fib_lookup+0xec/0x1e0 net/ipv4/fib_rules.c:95 fib_lookup.constprop.0+0x35c/0x530 include/net/ip_fib.h:382 ip_route_output_key_hash_rcu+0xde2/0x28f0 net/ipv4/route.c:2803 ip_route_output_key_hash+0x137/0x2e0 net/ipv4/route.c:2694 __ip_route_output_key include/net/route.h:169 [inline] ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2921 ip_route_output_key include/net/route.h:179 [inline] ip_route_me_harder+0x565/0x12f0 net/ipv4/netfilter.c:53 synproxy_send_tcp.isra.0+0x2fa/0x630 net/netfilter/nf_synproxy_core.c:431 synproxy_send_client_synack+0x6f6/0x8f0 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline] nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e9/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:272 NF_HOOK include/linux/netfilter.h:315 [inline] ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:469 [inline] ip_rcv_finish net/ipv4/ip_input.c:448 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] NF_HOOK include/linux/netfilter.h:311 [inline] ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:568 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5977 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6090 process_backlog+0x442/0x15e0 net/core/dev.c:6442 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605 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: 6b 6d 02 e9 83 fb 02 00 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 43 89 23 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6 RAX: 00000000028dceb3 RBX: 0000000000000000 RCX: ffffffff8b868c99 RDX: 0000000000000000 RSI: ffffffff8de300f6 RDI: ffffffff8c157460 RBP: fffffbfff1c52ef0 R08: 0000000000000001 R09: ffffed1017086645 R10: ffff8880b843322b R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e297780 R14: ffffffff90a94150 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:745 start_kernel+0x3ee/0x4d0 init/main.c:1102 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