bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:1) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P22899/1:b..l rcu: (detected by 0, t=10502 jiffies, g=110993, q=997 ncpus=2) task:syz.3.4612 state:R running task stack:26784 pid:22899 tgid:22895 ppid:18232 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0xe1/0x130 kernel/softirq.c:457 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:914 [inline] __dev_queue_xmit+0x1edc/0x3820 net/core/dev.c:4913 dev_queue_xmit include/linux/netdevice.h:3448 [inline] __netlink_deliver_tap_skb net/netlink/af_netlink.c:308 [inline] __netlink_deliver_tap+0x5b4/0x860 net/netlink/af_netlink.c:326 netlink_deliver_tap+0x19c/0x1b0 net/netlink/af_netlink.c:339 __netlink_sendskb net/netlink/af_netlink.c:1261 [inline] netlink_sendskb+0x68/0x140 net/netlink/af_netlink.c:1270 netlink_rcv_skb+0x2a4/0x4a0 net/netlink/af_netlink.c:2562 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 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: 0033:0x7f8ea599e0d9 RSP: 002b:00007f8ea67a5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f8ea5c26180 RCX: 00007f8ea599e0d9 RDX: 0000000000000000 RSI: 00002000000012c0 RDI: 0000000000000005 RBP: 00007f8ea5a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8ea5c26218 R14: 00007f8ea5c26180 R15: 00007ffefa8e4f48 rcu: rcu_preempt kthread starved for 7190 jiffies! g110993 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:27752 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18817 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:match_held_lock+0x7d/0xb0 kernel/locking/lockdep.c:5337 Code: 10 35 16 94 48 29 d0 48 c1 f8 03 48 ba 29 5c 8f c2 f5 28 5c 8f 48 0f af d0 bb 01 00 00 00 48 39 ca 74 02 31 db 89 d8 5b 41 5e cc cc cc cc cc 90 e8 77 60 fd f8 85 c0 74 1c 83 3d 80 37 85 04 RSP: 0018:ffffc90000a07d08 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff88802667e968 RCX: 0000000000000101 RDX: ffff88802667dd00 RSI: ffffffff8eb59c60 RDI: ffff88802667e968 RBP: 00000000ffffffff R08: ffff88802667dd00 R09: 0000000000000004 R10: 0000000000000003 R11: ffffffff8aad0e10 R12: 0000000000000246 R13: ffff88802667dd00 R14: ffffffff8eb59c60 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff888125049000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff817235067 CR3: 000000000e946000 CR4: 00000000003526f0 Call Trace: __lock_is_held kernel/locking/lockdep.c:5601 [inline] lock_is_held_type+0x89/0x150 kernel/locking/lockdep.c:5940 br_port_get_rcu net/bridge/br_private.h:459 [inline] bridge_parent net/bridge/br_netfilter_hooks.c:164 [inline] br_nf_post_routing+0xfe/0xee0 net/bridge/br_netfilter_hooks.c:930 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 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:6103 __netif_receive_skb_one_core net/core/dev.c:6214 [inline] __netif_receive_skb net/core/dev.c:6329 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6680 __napi_poll+0xaa/0x330 net/core/dev.c:7739 napi_poll net/core/dev.c:7802 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7959 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 1e 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 8e 1a 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 1a 0c RSP: 0018:ffffc90003797700 EFLAGS: 00000293 RAX: ffffffff81bae6ed RBX: dffffc0000000000 RCX: ffff88802667dd00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003797860 R08: ffffffff90578f37 R09: 1ffffffff20af1e6 R10: dffffc0000000000 R11: fffffbfff20af1e7 R12: 1ffff110170c85fd R13: ffff8880b873c448 R14: ffff8880b8642fe8 R15: 0000000000000000 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: 5755 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:1) net_ratelimit: 6795 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:e2:52:b0:ab:f9:66, vlan:1)