bridge0: received packet on bridge_slave_0 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): P23972/1:b..l rcu: (detected by 0, t=10503 jiffies, g=129373, q=3999 ncpus=2) task:syz-executor state:R running task stack:22336 pid:23972 tgid:23972 ppid:23968 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 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:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872 Code: e9 30 ff ff ff e8 45 95 0f 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 c1 02 7b 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d be 4d 73 RSP: 0018:ffffc90004f2f398 EFLAGS: 00000282 RAX: 74473ee9b7cf2a00 RBX: 0000000000000246 RCX: 0000000000000046 RDX: 000000000973479e RSI: ffffffff8e19b9cd RDI: ffffffff8c27ca80 RBP: 0000000000000000 R08: ffffffff81767e95 R09: ffffffff8e75e620 R10: ffffc90004f2f4f8 R11: ffffffff81b0cfd0 R12: 0000000000000002 R13: ffffffff8e75e620 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23c0 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 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_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5573 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4873 dup_fd+0x55/0xb40 fs/file.c:390 copy_files+0xc8/0x120 kernel/fork.c:1636 copy_process+0x175f/0x3cd0 kernel/fork.c:2211 kernel_clone+0x248/0x8e0 kernel/fork.c:2653 __do_sys_clone kernel/fork.c:2794 [inline] __se_sys_clone kernel/fork.c:2778 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2778 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1fcdfc5292 RSP: 002b:00007ffd81653440 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd81653440 RCX: 00007f1fcdfc5292 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd816535cc R08: 0000000000000000 R09: 0000000000000001 R10: 00005555945f37d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000000a89fd R15: 00007ffd81653620 rcu: rcu_preempt kthread starved for 2058 jiffies! g129373 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:26760 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 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:436 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: 1002 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:match_held_lock+0x0/0xb0 kernel/locking/lockdep.c:5305 Code: 67 48 0f b9 3a 90 31 db 48 89 d8 5b 41 5e 41 5f c3 cc cc cc cc cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 56 53 bb 01 00 00 00 48 39 77 10 74 6a 81 7f 20 00 00 20 00 72 RSP: 0018:ffffc90000a07c58 EFLAGS: 00000083 RAX: 0000000000000007 RBX: ffff888027800c48 RCX: 0000000080000102 RDX: ffff888027800000 RSI: ffff88807c059588 RDI: ffff888027800c48 RBP: 00000000ffffffff R08: 0000000000000004 R09: 0000000000a08003 R10: 0000000000000003 R11: 0000000000000100 R12: 0000000000000246 R13: ffff888027800000 R14: ffff88807c059588 R15: 0000000000000006 FS: 0000000000000000(0000) GS:ffff888125557000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000009b6030 CR3: 000000000e54c000 CR4: 00000000003526f0 Call Trace: __lock_is_held kernel/locking/lockdep.c:5601 [inline] lock_is_held_type+0x89/0x150 kernel/locking/lockdep.c:5940 lock_is_held include/linux/lockdep.h:249 [inline] __br_multicast_add_group+0x321/0xa30 net/bridge/br_multicast.c:1528 br_multicast_add_group net/bridge/br_multicast.c:1567 [inline] br_ip6_multicast_add_group net/bridge/br_multicast.c:1619 [inline] br_ip6_multicast_mld2_report net/bridge/br_multicast.c:3038 [inline] br_multicast_ipv6_rcv net/bridge/br_multicast.c:3976 [inline] br_multicast_rcv+0x3b8f/0x7650 net/bridge/br_multicast.c:4034 br_handle_frame_finish+0x775/0x1bb0 net/bridge/br_input.c:156 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/0x31a0 net/core/dev.c:6077 __netif_receive_skb_one_core net/core/dev.c:6188 [inline] __netif_receive_skb net/core/dev.c:6303 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6654 __napi_poll+0xae/0x340 net/core/dev.c:7718 napi_poll net/core/dev.c:7781 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7938 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x70 kernel/kcov.c:217 Code: 88 e1 56 11 65 8b 15 a9 e1 56 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 a4 16 00 00 00 74 2c 8b 91 80 16 00 00 <83> fa 02 75 21 48 8b 91 88 16 00 00 48 8b 32 48 8d 7e 01 8b 89 84 RSP: 0018:ffffc900046ff6f8 EFLAGS: 00000246 RAX: ffffffff81b9cc2d RBX: 1ffff110170c8525 RCX: ffff888027800000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900046ff840 R08: ffffffff901187b7 R09: 1ffffffff20230f6 R10: dffffc0000000000 R11: fffffbfff20230f7 R12: ffff8880b8642928 R13: dffffc0000000000 R14: ffff8880b873c000 R15: 0000000000000000 csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0xcfd/0x12c0 kernel/smp.c:877 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2761 [inline] smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2971 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:900 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 lec0: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 5010 ms lec:lec_tx_timeout: lec0 lec:lec_start_xmit: lec0:No lecd attached net_ratelimit: 15164 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:7e:f6:e2:90:07:17, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) lec0: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 5010 ms lec:lec_tx_timeout: lec0 net_ratelimit: 16796 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:7e:f6:e2:90:07:17, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) lec:lec_start_xmit: lec0:No lecd attached