bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10040/1:b..l rcu: (detected by 0, t=10503 jiffies, g=39397, q=1533 ncpus=2) task:syz.4.1111 state:R running task stack:25592 pid:10040 tgid:10040 ppid:5634 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0xe1/0x130 kernel/softirq.c:457 nl80211_netlink_notify+0x46b/0x840 net/wireless/nl80211.c:22542 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380 netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761 __sock_release net/socket.c:722 [inline] sock_close+0xc3/0x240 net/socket.c:1514 __fput+0x44f/0xa60 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98 __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+0x353/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f893759ce59 RSP: 002b:00007ffe6c9ff308 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f8937817da0 RCX: 00007f893759ce59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f8937817da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f8937817cb0 R11: 0000000000000246 R12: 000000000003290c R13: 00007f893781618c R14: 00000000000326ef R15: 00007ffe6c9ff410 rcu: rcu_preempt kthread starved for 5090 jiffies! g39397 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:27536 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 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+0x389/0x470 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 87 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:rcu_rdp_cpu_online kernel/rcu/tree.c:4007 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x87/0x120 kernel/rcu/tree.c:4048 Code: 3c 30 00 74 08 48 89 df e8 86 f5 85 00 48 8b 03 48 8d 98 c0 0e 39 93 48 8d b8 e8 0e 39 93 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <74> 05 e8 62 f5 85 00 4c 8b 7b 28 48 83 c3 20 48 89 d8 48 c1 e8 03 RSP: 0018:ffffc90000a08170 EFLAGS: 00000246 RAX: 1ffff110170e77dd RBX: ffff8880b873bec0 RCX: 0000000000000102 RDX: ffff88801d7cdd00 RSI: ffffffff8c28b5c0 RDI: ffff8880b873bee8 RBP: ffffc90000a08290 R08: 000000000caaaaaa R09: 1ffff92000141044 R10: dffffc0000000000 R11: fffff52000141045 R12: dffffc0000000000 R13: 1ffff92000141040 R14: dffffc0000000000 R15: ffff8880699ae400 FS: 0000000000000000(0000) GS:ffff8881253ab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff843badeb8 CR3: 000000000e74a000 CR4: 00000000003526f0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_any_held+0x1e/0x90 kernel/rcu/update.c:384 __rhashtable_lookup include/linux/rhashtable.h:626 [inline] rhashtable_lookup include/linux/rhashtable.h:671 [inline] fdb_find_rcu+0x129/0x770 net/bridge/br_fdb.c:216 br_fdb_update+0x10e/0x690 net/bridge/br_fdb.c:981 br_handle_frame_finish+0x573/0x1c80 net/bridge/br_input.c:144 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x91f/0xc30 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: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+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6089 __netif_receive_skb_one_core net/core/dev.c:6200 [inline] __netif_receive_skb net/core/dev.c:6315 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6666 __napi_poll+0xae/0x340 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7953 handle_softirqs+0x22a/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:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xfcf/0x13d0 kernel/smp.c:892 Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 7a 06 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 02 0c 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 0a 02 0c RSP: 0018:ffffc900024cf700 EFLAGS: 00000293 RAX: ffffffff81b9c496 RBX: ffff8880b873c188 RCX: ffff88801d7cdd00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900024cf840 R08: ffffffff902ff2f7 R09: 1ffffffff205fe5e R10: dffffc0000000000 R11: fffffbfff205fe5f R12: 1ffff110170c8591 R13: dffffc0000000000 R14: ffff8880b8642c88 R15: 0000000000000000 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 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+0x5f5/0x1160 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:906 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 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: 7732 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) net_ratelimit: 8510 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:ba:f5:68:56:d0:8b, vlan:0)