bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=158661, q=1535 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 924 (4295048689-4295047765), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 924 jiffies! g158661 f0x2 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11313 Comm: kworker/u8:22 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:lock_is_held_type+0x7/0x150 kernel/locking/lockdep.c:5925 Code: c6 5f bb 42 8e 67 48 0f b9 3a 90 eb ce 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 <41> 56 41 55 41 54 53 bb ff ff ff ff 83 3d d6 bd 86 04 00 0f 84 e4 RSP: 0018:ffffc90000007250 EFLAGS: 00000202 RAX: 1ffffffff1d6bf01 RBX: 0000000000000000 RCX: 0000000000000102 RDX: ffff88802ca35d00 RSI: 00000000ffffffff RDI: ffffffff8eb59c60 RBP: 0000000000000001 R08: ffff88802ca35d00 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000100 R12: 0000000000000001 R13: 1ffff1100e7442d3 R14: 1ffff1100e7442d3 R15: ffff888031fbb400 FS: 0000000000000000(0000) GS:ffff888124f4e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055789146a4b0 CR3: 000000000e946000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000086 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] rcu_read_lock_any_held+0x33/0x90 kernel/rcu/update.c:386 __rht_ptr_rcu include/linux/rhashtable.h:390 [inline] __rhashtable_lookup include/linux/rhashtable.h:633 [inline] rhashtable_lookup include/linux/rhashtable.h:673 [inline] br_mdb_ip_get_rcu+0x1bd/0x650 net/bridge/br_multicast.c:102 br_mdb_entry_skb_get+0x587/0x7c0 net/bridge/br_multicast.c:198 br_handle_frame_finish+0xde6/0x1990 net/bridge/br_input.c:188 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x127f/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6099 __netif_receive_skb_one_core net/core/dev.c:6210 [inline] __netif_receive_skb net/core/dev.c:6325 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6676 __napi_poll+0xaa/0x330 net/core/dev.c:7735 napi_poll net/core/dev.c:7798 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7955 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x11e6/0x15f0 kernel/smp.c:912 Code: c0 75 7a 41 8b 1e 89 de 83 e6 01 31 ff e8 e2 22 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 8e 1e 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 73 1e 0c RSP: 0018:ffffc90004d87700 EFLAGS: 00000293 RAX: ffffffff81baf58d RBX: dffffc0000000000 RCX: ffff88802ca35d00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004d87860 R08: ffffffff90579237 R09: 1ffffffff20af246 R10: dffffc0000000000 R11: fffffbfff20af247 R12: 1ffff110170e81d1 R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1077 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline] smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:911 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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 net_ratelimit: 14566 callbacks suppressed ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on veth1_to_bridge with own address as source address (addr:9e:90:e3:b0:02:4d, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 17109 callbacks suppressed ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)