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): P31527 rcu: (detected by 1, t=10503 jiffies, g=172345, q=2087 ncpus=2) task:syz.0.6491 state:R running task stack:26624 pid:31527 tgid:31526 ppid:28844 task_flags:0x40044c flags:0x00080003 Call Trace: sched_show_task+0x4aa/0x5f0 kernel/sched/core.c:8184 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline] print_other_cpu_stall+0xf7d/0x1310 kernel/rcu/tree_stall.h:680 check_cpu_stall kernel/rcu/tree_stall.h:855 [inline] rcu_pending kernel/rcu/tree.c:3708 [inline] rcu_sched_clock_irq+0x93d/0x1050 kernel/rcu/tree.c:2744 update_process_times+0x23b/0x2f0 kernel/time/timer.c:2475 tick_sched_handle kernel/time/tick-sched.c:296 [inline] tick_nohz_handler+0x38f/0x6b0 kernel/time/tick-sched.c:317 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x371/0xa10 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:stack_trace_consume_entry+0x0/0x280 kernel/stacktrace.c:83 Code: f0 5b 41 5e 5d c3 cc cc cc cc cc e8 fa 29 1f 0a 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 ba 00 00 RSP: 0018:ffffc90000a07b40 EFLAGS: 00000282 RAX: ffffffff82345c5e RBX: ffffc90000a07c00 RCX: 0000000080000100 RDX: 0000000000000001 RSI: ffffffff82345c5e RDI: ffffc90000a07c00 RBP: ffffc90000a07bd0 R08: ffffc90000a07c80 R09: 0000000000000000 R10: ffffc90000a07b98 R11: ffffffff81b1fa10 R12: ffff88803630dd00 R13: 0000000000000000 R14: ffffffff81b1fa10 R15: ffffc90000a07b48 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+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 skb_ext_reset include/linux/skbuff.h:5117 [inline] skb_release_head_state+0x270/0x360 net/core/skbuff.c:1183 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x24/0x210 net/core/skbuff.c:1205 kfree_skb_reason include/linux/skbuff.h:1323 [inline] kfree_skb include/linux/skbuff.h:1332 [inline] ip6_mc_input+0x909/0xbc0 net/ipv6/ip6_input.c:638 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:988 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323 __netif_receive_skb_one_core net/core/dev.c:6215 [inline] __netif_receive_skb net/core/dev.c:6328 [inline] netif_receive_skb_internal net/core/dev.c:6414 [inline] netif_receive_skb+0x278/0xbf0 net/core/dev.c:6473 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:325 br_handle_frame_finish+0x1192/0x1990 net/bridge/br_input.c:-1 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:325 [inline] br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:165 [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:6102 __netif_receive_skb_one_core net/core/dev.c:6213 [inline] __netif_receive_skb net/core/dev.c:6328 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6679 __napi_poll+0xaa/0x330 net/core/dev.c:7738 napi_poll net/core/dev.c:7801 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7958 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 nl80211_netlink_notify+0x49c/0x860 net/wireless/nl80211.c:23145 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380 netlink_release+0x11f8/0x1a80 net/netlink/af_netlink.c:762 __sock_release net/socket.c:710 [inline] sock_close+0xad/0x220 net/socket.c:1501 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1009 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f44f2f5e6ce Code: Unable to access opcode bytes at 0x7f44f2f5e6a4. RSP: 002b:00007f44f3e52e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: 0000000000000020 RBX: 00007f44f3e546c0 RCX: 00007f44f2f5e6ce RDX: 0000000000000020 RSI: 00007f44f3e53000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f44f3e52f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 00007f44f3e52f58 R14: 00007f44f3e53000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 2402 jiffies! g172345 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:26848 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: 48 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: events_dfl_long defense_work_handler RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4879 [inline] RIP: 0010:__lock_acquire+0x52e/0x2cf0 kernel/locking/lockdep.c:5187 Code: 00 48 83 c3 28 41 89 c4 49 39 cf 0f 8d a4 00 00 00 49 83 ff 31 0f 83 83 00 00 00 8b 03 25 ff 1f 00 00 48 0f a3 05 d2 d8 d1 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 10 95 15 94 eb 32 83 3d 99 68 RSP: 0018:ffffc90000006038 EFLAGS: 00000003 RAX: 0000000000000419 RBX: ffff888020ef2b88 RCX: 0000000000000007 RDX: 0000000000000003 RSI: 0000000000000003 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff8177827f R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 0000000000000003 R13: ffff888020ef2bb8 R14: ffff888020ef1f00 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff888124f53000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2044e9dfa4 CR3: 0000000036e0a000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 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 skb_ext_reset include/linux/skbuff.h:5117 [inline] skb_scrub_packet+0x2c8/0x3d0 net/core/skbuff.c:6278 ____dev_forward_skb include/linux/netdevice.h:4478 [inline] __dev_forward_skb2+0x28c/0x730 net/core/dev.c:2444 veth_forward_skb drivers/net/veth.c:324 [inline] veth_xmit+0x493/0xe60 drivers/net/veth.c:380 __netdev_start_xmit include/linux/netdevice.h:5424 [inline] netdev_start_xmit include/linux/netdevice.h:5433 [inline] xmit_one net/core/dev.c:3892 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3908 __dev_queue_xmit+0x14c0/0x3820 net/core/dev.c:4881 dev_queue_xmit include/linux/netdevice.h:3451 [inline] br_dev_queue_push_xmit+0x370/0x4b0 net/bridge/br_forward.c:53 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:325 br_nf_post_routing+0xa53/0xee0 net/bridge/br_netfilter_hooks.c:964 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:323 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:325 br_nf_forward_ip+0x7eb/0xa30 net/bridge/br_netfilter_hooks.c:721 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:323 __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:325 [inline] br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:165 [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:6102 __netif_receive_skb_one_core net/core/dev.c:6213 [inline] __netif_receive_skb net/core/dev.c:6328 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6679 __napi_poll+0xaa/0x330 net/core/dev.c:7738 napi_poll net/core/dev.c:7801 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7958 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 local_bh_enable include/linux/bottom_half.h:33 [inline] update_defense_level+0x867/0xcb0 net/netfilter/ipvs/ip_vs_ctl.c:210 defense_work_handler+0x2d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:235 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 ip6_tunnel: ip6tnl3 xmit: Local address not yet configured! net_ratelimit: 16009 callbacks suppressed 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 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 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 veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)