bridge0: received packet on veth0_to_bridge 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): P8556/1:b..l P8550/3:b..l rcu: (detected by 1, t=10503 jiffies, g=29397, q=1887 ncpus=2) task:syz.3.576 state:R running task stack:22072 pid:8550 tgid:8548 ppid:5820 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7092 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:457 local_bh_enable include/linux/bottom_half.h:33 [inline] __neigh_event_send+0x331/0x1430 net/core/neighbour.c:1279 neigh_event_send_probe include/net/neighbour.h:480 [inline] neigh_event_send include/net/neighbour.h:486 [inline] neigh_event_send include/net/neighbour.h:484 [inline] neigh_resolve_output+0x550/0x8f0 net/core/neighbour.c:1603 neigh_output include/net/neighbour.h:556 [inline] ip6_finish_output2+0xb0f/0x1ce0 net/ipv6/ip6_output.c:136 ip6_fragment+0xbff/0x2880 net/ipv6/ip6_output.c:1026 __ip6_finish_output+0xb06/0xdf0 net/ipv6/ip6_output.c:206 ip6_finish_output net/ipv6/ip6_output.c:219 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x2aa/0xa60 net/ipv6/ip6_output.c:246 dst_output include/net/dst.h:470 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip6_xmit+0x1006/0x24a0 net/ipv6/ip6_output.c:358 sctp_v6_xmit+0xd1a/0x1220 net/sctp/ipv6.c:248 sctp_packet_transmit+0x22ec/0x3060 net/sctp/output.c:653 sctp_packet_singleton+0x19e/0x370 net/sctp/outqueue.c:783 sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline] sctp_outq_flush+0x315/0x3350 net/sctp/outqueue.c:1212 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1824 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline] sctp_do_sm+0xce1/0x5be0 net/sctp/sm_sideeffect.c:1175 sctp_primitive_ASSOCIATE+0x9c/0xd0 net/sctp/primitive.c:73 sctp_sendmsg_to_asoc+0xa6a/0x1c50 net/sctp/socket.c:1840 sctp_sendmsg+0x1185/0x22b0 net/sctp/socket.c:2030 inet_sendmsg+0x11c/0x140 net/ipv4/af_inet.c:859 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x446/0x4b0 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff5eaf9c799 RSP: 002b:00007ff5ebe90028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007ff5eb215fa0 RCX: 00007ff5eaf9c799 RDX: 0000000000000401 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007ff5eb032bd9 R08: 0000200000000000 R09: 000000000000001f R10: 0000000000000101 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff5eb216038 R14: 00007ff5eb215fa0 R15: 00007ffc21ad8818 task:syz.3.576 state:R running task stack:27960 pid:8556 tgid:8556 ppid:8550 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7092 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:389 [inline] zap_pte_range mm/memory.c:1959 [inline] zap_pmd_range mm/memory.c:2021 [inline] zap_pud_range mm/memory.c:2049 [inline] zap_p4d_range mm/memory.c:2070 [inline] unmap_page_range+0x152f/0x4840 mm/memory.c:2091 unmap_single_vma+0x153/0x240 mm/memory.c:2133 unmap_vmas+0x295/0x590 mm/memory.c:2171 exit_mmap+0x1ef/0xa30 mm/mmap.c:1302 __mmput+0x12a/0x410 kernel/fork.c:1174 mmput+0x67/0x80 kernel/fork.c:1197 exit_mm kernel/exit.c:581 [inline] do_exit+0x819/0x2b60 kernel/exit.c:964 __do_sys_exit kernel/exit.c:1085 [inline] __se_sys_exit kernel/exit.c:1083 [inline] __x64_sys_exit+0x42/0x50 kernel/exit.c:1083 x64_sys_call+0x152e/0x1530 arch/x86/include/generated/asm/syscalls_64.h:61 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff5eaf9c799 RSP: 002b:00007ff5ebe8ffd8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c RAX: ffffffffffffffda RBX: 00007ff5eb215fa0 RCX: 00007ff5eaf9c799 RDX: 00007ff5ebe909c8 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff5eb032bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff5eb216038 R14: 00007ff5eb215fa0 R15: 00007ffc21ad8818 rcu: rcu_preempt kthread starved for 10056 jiffies! g29397 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:29080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7005 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 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: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:313 Code: 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 58 fe ff ff 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 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 2a fe ff ff RSP: 0018:ffffc90000a07a08 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff895f3c35 RDX: ffff88801e6e8000 RSI: 00000000ffffffff RDI: 00000000ffffffff RBP: ffff888027b06140 R08: 0000000000000005 R09: 0000000000000001 R10: 0000000000000002 R11: 0000000000000000 R12: ffff88807bd10000 R13: ffff88807bd10000 R14: 1ffff92000140f44 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812444d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f465e347faf CR3: 0000000073310000 CR4: 00000000003526f0 Call Trace: netdev_pick_tx+0x9c/0xe50 net/core/dev.c:4676 netdev_core_pick_tx+0x285/0x300 net/core/dev.c:4713 __dev_queue_xmit+0x40e/0x4800 net/core/dev.c:4796 dev_queue_xmit include/linux/netdevice.h:3384 [inline] br_dev_queue_push_xmit+0x360/0x550 net/bridge/br_forward.c:53 br_nf_dev_queue_xmit+0x741/0x2a20 net/bridge/br_netfilter_hooks.c:920 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_post_routing+0xcbb/0x16a0 net/bridge/br_netfilter_hooks.c:966 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK include/linux/netfilter.h:316 [inline] br_forward_finish+0x261/0x4d0 net/bridge/br_forward.c:66 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1167 br_nf_forward_finish+0x693/0xb30 net/bridge/br_netfilter_hooks.c:662 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_forward_ip.part.0+0x61e/0x820 net/bridge/br_netfilter_hooks.c:716 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:676 [inline] br_nf_forward+0xfe5/0x19f0 net/bridge/br_netfilter_hooks.c:773 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK include/linux/netfilter.h:316 [inline] __br_forward+0x2f6/0x970 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] br_flood+0x37f/0x650 net/bridge/br_forward.c:250 br_handle_frame_finish+0xff0/0x1f60 net/bridge/br_input.c:229 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1167 br_nf_pre_routing_finish_ipv6+0x769/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x93b/0x1510 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0xcdd/0x1520 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0x6c5/0x3550 net/core/dev.c:6051 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6162 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6277 process_backlog+0x37a/0x1580 net/core/dev.c:6628 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7912 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xef/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+0xa3/0xc0 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:63 Code: d8 85 02 c3 cc cc cc cc 0f 1f 00 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 23 ae 1e 00 fb f4 fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000242 RAX: 0000000000f01525 RBX: ffff88801e6e8000 RCX: ffffffff8b8cdc75 RDX: 0000000000000000 RSI: ffffffff8de7be29 RDI: ffffffff8c1af7a0 RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed10170a6795 R10: ffff8880b8533cab R11: 0000000000000000 R12: ffffed1003cdd000 R13: 0000000000000001 R14: ffffffff90d9b710 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x35b/0x4b0 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148 net_ratelimit: 15633 callbacks suppressed 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:0c, 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: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:0c, 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:aa:aa:aa:aa:aa:0c, 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:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)