bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21380/1:b..l rcu: (detected by 1, t=10503 jiffies, g=253117, q=718 ncpus=2) task:syz-executor state:R running task stack:21592 pid:21380 tgid:21380 ppid:1 task_flags:0x40054c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ef/0x4fb0 kernel/sched/core.c:6867 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7051 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_read_unlock include/linux/rwlock_api_smp.h:233 [inline] _raw_read_unlock+0x3f/0x50 kernel/locking/spinlock.c:260 zap_pid_ns_processes+0x2c9/0x5f0 kernel/pid_namespace.c:233 find_child_reaper kernel/exit.c:622 [inline] forget_original_parent kernel/exit.c:706 [inline] exit_notify kernel/exit.c:743 [inline] do_exit+0x1eff/0x2310 kernel/exit.c:983 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd11035b58e RSP: 002b:00007fd11073fd28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 000055558838c500 RCX: 00007fd11035b58e RDX: 00007fd11073fd80 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fd11073fdec R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000001f5 R13: 0000000000000012 R14: 00000000002330b1 R15: 00007fd11073fe40 rcu: rcu_preempt kthread starved for 1275 jiffies! g253117 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:27680 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ef/0x4fb0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x1560 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:2285 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 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: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 RIP: 0010:nf_nat_ipv6_fn+0xf8/0x2f0 net/netfilter/nf_nat_proto.c:913 Code: 90 97 83 8f e8 d9 d4 1d f8 41 83 fc 01 74 20 41 83 fc 04 0f 85 13 01 00 00 e8 44 cf 1d f8 eb 14 e8 3d cf 1d f8 b8 01 00 00 00 2c 01 00 00 e8 2e cf 1d f8 4c 89 7c 24 10 48 8d bb d0 00 00 00 RSP: 0018:ffffc900000078e0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffff88808046c500 RCX: ffffffff8e0953c0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007990 R08: 00000000000002ff R09: 0200000000000000 R10: 00000000000002ff R11: 0200000000000000 R12: 0000000000000000 R13: 1ffff92000000f20 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125928000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000243030 CR3: 000000000e146000 CR4: 00000000003526f0 Call Trace: nf_nat_ipv6_in+0xff/0x2c0 net/netfilter/nf_nat_proto.c:962 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6152 [inline] __netif_receive_skb+0xd3/0x370 net/core/dev.c:6265 process_backlog+0x54e/0x1340 net/core/dev.c:6617 __napi_poll+0xae/0x320 net/core/dev.c:7681 napi_poll net/core/dev.c:7744 [inline] net_rx_action+0x696/0xe30 net/core/dev.c:7896 handle_softirqs+0x22a/0x7c0 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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 28 5f 02 e9 d3 e5 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 b7 10 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e007dc0 EFLAGS: 00000242 RAX: 000000000388a189 RBX: ffffffff8198427d RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dacfb53 RDI: ffffffff8be73880 RBP: ffffffff8e007eb0 R08: ffff8880b86336db R09: 1ffff110170c66db R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8fced970 R13: 1ffffffff1c12a78 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1bd/0x500 kernel/sched/idle.c:332 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x380/0x3d0 init/main.c:1206 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 net_ratelimit: 13270 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:fe:0c:c3:1a:51:90, 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 veth0_to_bridge with own address as source address (addr:fe:0c:c3:1a:51:90, 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 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 veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 16604 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:fe:0c:c3:1a:51:90, 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 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 veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:fe:0c:c3:1a:51:90, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)