bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5632/2:b..l rcu: (detected by 0, t=10502 jiffies, g=45821, q=768 ncpus=2) task:syz-executor state:R running task stack:22088 pid:5632 tgid:5632 ppid:5620 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:kill_pid_info_type+0xf8/0x1f0 kernel/signal.c:1466 Code: 4c 89 f7 31 f6 e8 88 78 05 00 48 89 c3 48 85 c0 74 1d e8 9b 51 3c 00 89 ef 4c 89 ee 48 89 da 44 89 fd 44 89 f9 e8 48 f6 ff ff <41> 89 c5 eb 0e 44 89 fd e8 7b 51 3c 00 41 bd fd ff ff ff e8 80 aa RSP: 0018:ffffc9000466fd68 EFLAGS: 00000296 RAX: 0000000000000000 RBX: ffff88801df85d00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e22ba9f RDI: 00000000ffffffff RBP: 0000000000000001 R08: ffffffff905785f7 R09: 1ffffffff20af0be R10: dffffc0000000000 R11: fffffbfff20af0bf R12: ffffffff818a1f33 R13: ffffc9000466fe20 R14: ffff888073681680 R15: 0000000000000001 kill_pid_info kernel/signal.c:1480 [inline] kill_proc_info+0xd9/0x180 kernel/signal.c:1487 kill_something_info kernel/signal.c:1584 [inline] __do_sys_kill kernel/signal.c:3965 [inline] __se_sys_kill+0xd9/0x460 kernel/signal.c:3959 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4aa333f427 RSP: 002b:00007fff834f3938 EFLAGS: 00000217 ORIG_RAX: 000000000000003e RAX: ffffffffffffffda RBX: 00000000000003b0 RCX: 00007f4aa333f427 RDX: 0000000000000178 RSI: 0000000000000009 RDI: 00000000000003b0 RBP: 00007fff834f397c R08: 00000000166f2d0d R09: 0000000000000000 R10: 4000000000000000 R11: 0000000000000217 R12: 0000000000000143 R13: 0000000000000064 R14: 000000000004e378 R15: 00007fff834f39d0 rcu: rcu_preempt kthread starved for 5977 jiffies! g45821 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: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: CPU: 0 UID: 0 PID: 5737 Comm: kworker/0:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 61 9f 2d 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 4b 9a ca 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 98 ed b8 RSP: 0018:ffffc90000006200 EFLAGS: 00000286 RAX: 3fb36abf74db2b00 RBX: 0000000000000000 RCX: 0000000080000301 RDX: 00000000633d45e1 RSI: ffffffff8e4b0ac6 RDI: ffffffff8c4bda80 RBP: ffffffff8176f27f R08: ffffffff8176f27f R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 0000000000000002 R13: ffffffff8eb59c60 R14: 0000000000000000 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff888124f54000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564664279168 CR3: 000000007de4e000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 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+0x40/0x50 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:2705 [inline] slab_free mm/slub.c:6405 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6532 packet_rcv+0x16e/0x16f0 net/packet/af_packet.c:2224 dev_queue_xmit_nit+0xa2c/0xac0 net/core/dev.c:2607 xmit_one net/core/dev.c:3885 [inline] dev_hard_start_xmit+0x1c1/0x830 net/core/dev.c:3905 __dev_queue_xmit+0x14c0/0x3820 net/core/dev.c:4878 dev_queue_xmit include/linux/netdevice.h:3446 [inline] br_dev_queue_push_xmit+0x370/0x4b0 net/bridge/br_forward.c:53 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_post_routing+0xa53/0xee0 net/bridge/br_netfilter_hooks.c:964 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+0x23e/0x3f0 include/linux/netfilter.h:316 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1165 [inline] br_nf_forward_finish+0xa76/0xea0 net/bridge/br_netfilter_hooks.c:667 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_forward_ip+0x7eb/0xa30 net/bridge/br_netfilter_hooks.c:721 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+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+0x3e6/0x8d0 net/bridge/br_forward.c:245 br_handle_frame_finish+0x1175/0x1990 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+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+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] neigh_periodic_work+0xc23/0xe40 net/core/neighbour.c:1035 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 bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:1e:05:6d:08:c4:e8, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:1e:05:6d:08:c4:e8, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)