rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=42297, q=897 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 1768 (4294980959-4294979191), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 1769 jiffies! g42297 f0x2 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:28192 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: CPU: 1 UID: 0 PID: 7801 Comm: kworker/R-bond3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: bond3 bond_mii_monitor RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d d4 be 88 0c 48 89 de 5b e9 73 09 62 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 78 fe a5 11 65 8b 15 99 fe a5 RSP: 0018:ffffc90000a07f18 EFLAGS: 00000286 RAX: ffffffff8a859ec4 RBX: 0000000000000001 RCX: ffff8880299a1f00 RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff8a859c3e R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000 R13: 1ffff11010acfdb6 R14: ffff88808567eda8 R15: ffff8880329f6800 FS: 0000000000000000(0000) GS:ffff888125050000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055bf129fd168 CR3: 000000000e946000 CR4: 00000000003526f0 Call Trace: ipv6_chk_mcast_addr+0x2c9/0x860 net/ipv6/mcast.c:1052 ip6_mc_input+0x510/0xbc0 net/ipv6/ip6_input.c:575 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:988 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+0x21f/0x3c0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6212 [inline] __netif_receive_skb net/core/dev.c:6325 [inline] netif_receive_skb_internal net/core/dev.c:6411 [inline] netif_receive_skb+0x278/0xbf0 net/core/dev.c:6470 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318 br_handle_frame_finish+0x1192/0x1990 net/bridge/br_input.c:-1 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:6099 __netif_receive_skb_one_core net/core/dev.c:6210 [inline] __netif_receive_skb net/core/dev.c:6325 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6676 __napi_poll+0xaa/0x330 net/core/dev.c:7735 napi_poll net/core/dev.c:7798 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7955 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:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893 Code: 5d ca 11 00 00 00 00 eb b5 e8 c5 3d 2e 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 b5 18 ca 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 9a 3e 31 0a cc 48 8d 3d 12 3a b8 RSP: 0018:ffffc9000384faa8 EFLAGS: 00000282 RAX: 82e3a9b77bb7c000 RBX: 0000000000000283 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8e4b24bb RDI: ffffffff8c4bdb80 RBP: ffff8880299a2aa0 R08: ffffffff90578f37 R09: 1ffffffff20af1e6 R10: dffffc0000000000 R11: fffffbfff20af1e7 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880548ad140 R15: ffff8880299a1f00 process_one_work kernel/workqueue.c:3331 [inline] process_scheduled_works+0xb26/0x14e0 kernel/workqueue.c:3405 rescuer_thread+0x7b6/0x10b0 kernel/workqueue.c:3629 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: 12931 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:c6:78:89:76:c7:54, vlan:0)