bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6755/1:b..l rcu: (detected by 0, t=10503 jiffies, g=158901, q=1594 ncpus=2) task:syz-executor state:R running task stack:22264 pid:6755 tgid:6755 ppid:1 task_flags:0x40054c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:60 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] RIP: 0010:unwind_next_frame+0xd73/0x23c0 arch/x86/kernel/unwind_orc.c:600 Code: 4c 24 20 0f b6 04 01 84 c0 0f 85 51 11 00 00 41 83 3e 00 0f 95 c0 49 39 df 0f 96 c1 20 c1 49 39 dc 0f 97 c0 20 c8 3c 01 75 18 <48> 8d 43 08 4c 39 f8 0f 97 c1 4c 39 e0 0f 96 c0 84 c1 0f 85 bf 00 RSP: 0018:ffffc9000c67ef98 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc9000c67f790 RCX: 1ffff920018cfe01 RDX: ffffffff90b309e0 RSI: 0000000000000002 RDI: ffffffff8c27a420 RBP: 1ffff920018cfe0e R08: 0000000000000001 R09: ffffffff8e7602e0 R10: ffffc9000c67f0b8 R11: ffffffff81b0b130 R12: ffffc9000c680000 R13: 1ffff920018cfe0f R14: ffffc9000c67f068 R15: ffffc9000c678000 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_unref_folios+0xed5/0x16d0 mm/page_alloc.c:3040 folios_put_refs+0x789/0x8d0 mm/swap.c:1002 free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:423 __tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline] tlb_batch_pages_flush mm/mmu_gather.c:151 [inline] tlb_flush_mmu_free mm/mmu_gather.c:398 [inline] tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:405 tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:530 exit_mmap+0x498/0xa10 mm/mmap.c:1315 __mmput+0x118/0x430 kernel/fork.c:1174 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x62e/0x2320 kernel/exit.c:959 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1079f9de2a RSP: 002b:00007fffb4081ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: 0000000000000000 RBX: 00007f107a1e5460 RCX: 00007f1079f9de2a RDX: 0000000000000080 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007fffb4081f1c R09: 0000000000000000 R10: 00007fffb4081f20 R11: 0000000000000246 R12: 00007fffb4081f20 R13: 00007fffb4081f1c R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 639 jiffies! g158901 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27664 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 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:467 ret_from_fork+0x51e/0xb90 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7183 Comm: kworker/u8:60 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker RIP: 0010:nf_hook_slow+0x17d/0x220 net/netfilter/core.c:622 Code: 10 e9 27 ff ff ff 48 8b 0c 24 80 e1 07 fe c1 38 c1 7c d2 48 8b 3c 24 e8 f1 16 6a f8 eb c7 e8 5a ee ff f7 bd 01 00 00 00 eb 6c 4e ee ff f7 bd 01 00 00 00 eb 60 83 fb 02 75 49 e8 3d ee ff f7 RSP: 0018:ffffc90000a07f30 EFLAGS: 00000246 RAX: 0000000000000003 RBX: 0000000000000001 RCX: ffff888036738000 RDX: 0000000000000100 RSI: ffffffff8fc43120 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff888036738000 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000100 R12: 0000000000000003 R13: ffff8880652eac28 R14: 1ffff1100ca5d580 R15: ffff8880652eac30 FS: 0000000000000000(0000) GS:ffff888125566000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff7280183c CR3: 000000003700e000 CR4: 00000000003526f0 Call Trace: nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x560/0x6e0 include/linux/netfilter.h:316 br_nf_forward_ip+0x7ef/0xa30 net/bridge/br_netfilter_hooks.c:716 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238 br_handle_frame_finish+0x1492/0x1b40 net/bridge/br_input.c:229 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x31a0 net/core/dev.c:6041 __netif_receive_skb_one_core net/core/dev.c:6152 [inline] __netif_receive_skb net/core/dev.c:6267 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6619 __napi_poll+0xae/0x340 net/core/dev.c:7683 napi_poll net/core/dev.c:7746 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7898 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 blake2s_compress+0xf9/0x1eb0 lib/crypto/x86/blake2s.h:42 blake2s_update+0x14b/0x450 lib/crypto/blake2s.c:119 hmac+0x1fc/0x3b0 drivers/net/wireguard/noise.c:324 kdf drivers/net/wireguard/noise.c:367 [inline] message_ephemeral+0x255/0x310 drivers/net/wireguard/noise.c:493 wg_noise_handshake_create_initiation+0x257/0x830 drivers/net/wireguard/noise.c:545 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18d/0x350 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 15075 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 17446 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:d4:ec:05:fc:6a, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)