rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5489/1:b..l rcu: (detected by 0, t=10502 jiffies, g=165041, q=1501 ncpus=2) task:dhcpcd state:R running task stack:20984 pid:5489 tgid:5489 ppid:5488 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7507 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg+0x91/0x230 arch/x86/kernel/unwind_orc.c:419 Code: 00 00 74 16 4c 89 f7 e8 2d 9e ba 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 4c 89 74 24 08 4d 8b 77 10 4c 89 fd 48 c1 ed 03 <0f> b6 44 35 00 84 c0 0f 85 3c 01 00 00 41 83 3f 00 0f 95 c0 4c 39 RSP: 0018:ffffc900026870e0 EFLAGS: 00000a06 RAX: fffffffffffffff0 RBX: ffffc90002680000 RCX: 0000000000000000 RDX: ffffc90002687248 RSI: dffffc0000000000 RDI: ffffc90002687208 RBP: 1ffff920004d0e41 R08: ffffc900026875d0 R09: 0000000000000000 R10: ffffc90002687258 R11: fffff520004d0e4d R12: 1ffff920004d0e42 R13: 1ffff920004d0e43 R14: ffffc90002688000 R15: ffffc90002687208 unwind_next_frame+0x19d5/0x2550 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5573 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4873 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_fork+0x14d/0x570 mm/rmap.c:394 dup_mmap+0x991/0x1d90 mm/mmap.c:1804 dup_mm kernel/fork.c:1533 [inline] copy_mm+0x13b/0x4a0 kernel/fork.c:1585 copy_process+0x1f1c/0x4450 kernel/fork.c:2261 kernel_clone+0x284/0x8f0 kernel/fork.c:2714 __do_sys_clone kernel/fork.c:2855 [inline] __se_sys_clone kernel/fork.c:2839 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2839 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6516314636 RSP: 002b:00007ffea8090330 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffea8090338 RCX: 00007f6516314636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffea80b0880 R08: 0000000000000000 R09: 0000000000000001 R10: 00007f6516240a50 R11: 0000000000000246 R12: 00007ffea8090470 R13: 0000000000000000 R14: 0000000000000000 R15: 0000557d366a3ac0 rcu: rcu_preempt kthread starved for 3245 jiffies! g165041 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] schedule+0x164/0x360 kernel/sched/core.c:7277 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 30031 Comm: kworker/0:21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: wg-crypt-wg2 wg_packet_encrypt_worker RIP: 0010:stack_trace_consume_entry+0x51/0x280 kernel/stacktrace.c:86 Code: 0f b6 44 15 00 84 c0 0f 85 09 01 00 00 44 8b 4f 10 4c 8d 77 08 4d 89 f5 49 c1 ed 03 41 0f b6 44 15 00 84 c0 0f 85 22 01 00 00 <45> 3b 0e 73 3a 48 8d 5f 0c 49 89 df 49 c1 ef 03 41 0f b6 04 17 84 RSP: 0018:ffffc90000006ed8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90000006fe0 RCX: 0000000080000100 RDX: dffffc0000000000 RSI: ffffffff89775213 RDI: ffffc90000006fe0 RBP: 1ffff92000000dfe R08: ffffc90000006ff0 R09: 0000000000000004 R10: ffffc90000006f78 R11: ffffffff81b0a9b0 R12: ffff888036b05c40 R13: 1ffff92000000dfd R14: ffffc90000006fe8 R15: ffffc90000006f28 FS: 0000000000000000(0000) GS:ffff888125245000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f97a500dff8 CR3: 000000000e74a000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x10f/0x150 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1c1/0x620 mm/slub.c:6483 skb_kfree_head net/core/skbuff.c:1075 [inline] skb_free_head net/core/skbuff.c:1087 [inline] skb_release_data+0x6c3/0x8f0 net/core/skbuff.c:1114 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1203 nft_synproxy_eval_v4+0x352/0x4e0 net/netfilter/nft_synproxy.c:61 nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x467/0x19f0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6209 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6673 __napi_poll+0xae/0x340 net/core/dev.c:7737 napi_poll net/core/dev.c:7800 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7957 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] ptr_ring_consume_bh include/linux/ptr_ring.h:377 [inline] wg_packet_encrypt_worker+0x2d2/0x1740 drivers/net/wireguard/send.c:293 process_one_work kernel/workqueue.c:3288 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245