bridge0: received packet on veth1_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): P12635/4:b..l rcu: (detected by 0, t=10503 jiffies, g=59637, q=1011 ncpus=2) task:syz.0.1788 state:R running task stack:24544 pid:12635 tgid:12629 ppid:5630 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x760 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:ip6_finish_output2+0xea4/0x13e0 net/ipv6/ip6_output.c:85 Code: ff ff e9 07 f7 ff ff e8 ea 9f 73 f7 e9 5b f6 ff ff e8 e0 9f 73 f7 90 0f 0b 90 43 80 3c 26 00 0f 85 fc f1 ff ff e9 ff f1 ff ff c7 9f 73 f7 eb 05 e8 c0 9f 73 f7 4b 8d 14 3e 48 83 c2 08 48 8b RSP: 0000:ffffc9000dff73c8 EFLAGS: 00000246 RAX: 1ffff1100faed000 RBX: ffff888077914d80 RCX: b039c93c80516200 RDX: ffffc90011438000 RSI: 000000000000d6e6 RDI: 000000000000d6e7 RBP: ffff88807d2ff000 R08: ffff8880311b5c40 R09: 0000000000000002 R10: 00000000fffffff5 R11: 0000000000000000 R12: ffff88807b232b40 R13: ffff88806877c710 R14: ffff8880770fe000 R15: 0000000000000010 ip6_fragment+0x1809/0x1e10 net/ipv6/ip6_output.c:994 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246 ip6_mr_output+0x549/0x11c0 net/ipv6/ip6mr.c:2415 ip6_send_skb+0x1d5/0x390 net/ipv6/ip6_output.c:2018 rawv6_push_pending_frames+0x65e/0x810 net/ipv6/raw.c:590 rawv6_sendmsg+0x1387/0x18e0 net/ipv6/raw.c:920 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x5de/0x710 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff37439ce59 RSP: 002b:00007ff3752fa028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007ff374616180 RCX: 00007ff37439ce59 RDX: 000000000000fff7 RSI: 0000200000000200 RDI: 000000000000000c RBP: 00007ff374432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000003b00 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff374616218 R14: 00007ff374616180 R15: 00007ffc404aed38 rcu: rcu_preempt kthread starved for 274 jiffies! g59637 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:26880 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 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+0x389/0x470 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: 59 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: krds_cp_wq#0/0 rds_connect_worker RIP: 0010:__lock_acquire+0x70/0x2cf0 kernel/locking/lockdep.c:-1 Code: 48 3d 80 33 fd 93 0f 84 da 13 00 00 41 89 cd 41 89 d6 8b 0d f2 f4 e0 0c 85 c9 44 0f 44 c1 31 c9 48 3d 70 33 fd 93 41 0f 45 c8 <89> 4c 24 10 8b 0d 56 0a a3 18 85 c9 0f 95 c0 83 fe 08 0f 92 c2 08 RSP: 0018:ffffc90000a07370 EFLAGS: 00000006 RAX: ffffffff9a48eba0 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e95cda0 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8e95cda0 R10: ffffc90000a07678 R11: ffffffff81b0efc0 R12: 0000000000000002 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812538a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5280947e20 CR3: 0000000036b74000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 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 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6250 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6377 skb_ext_del include/linux/skbuff.h:5099 [inline] nf_bridge_info_free net/bridge/br_netfilter_hooks.c:157 [inline] br_nf_dev_queue_xmit+0x4ee/0x25f0 net/bridge/br_netfilter_hooks.c:856 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_post_routing+0xb66/0xfe0 net/bridge/br_netfilter_hooks.c:964 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+0xa5e/0xe90 net/bridge/br_netfilter_hooks.c:667 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_forward_ip+0x7ef/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 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238 br_handle_frame_finish+0x1521/0x1c80 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+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/0x3170 net/core/dev.c:6089 __netif_receive_skb_one_core net/core/dev.c:6200 [inline] __netif_receive_skb net/core/dev.c:6315 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6666 __napi_poll+0xae/0x340 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7953 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] ip6_pol_route+0xf9d/0x13d0 net/ipv6/route.c:2325 pol_lookup_func include/net/ip6_fib.h:667 [inline] __fib6_rule_action net/ipv6/fib6_rules.c:240 [inline] fib6_rule_action+0x265/0xc00 net/ipv6/fib6_rules.c:278 fib_rules_lookup+0x768/0xea0 net/core/fib_rules.c:339 fib6_rule_lookup+0x1a0/0x730 net/ipv6/fib6_rules.c:115 ip6_route_output_flags_noref net/ipv6/route.c:2703 [inline] ip6_route_output_flags+0x364/0x5d0 net/ipv6/route.c:2715 ip6_dst_lookup_tail+0x2ae/0x15a0 net/ipv6/ip6_output.c:1186 ip6_dst_lookup_flow+0x89/0x150 net/ipv6/ip6_output.c:1291 tcp_v6_connect+0xcec/0x1b10 net/ipv6/tcp_ipv6.c:278 __inet_stream_connect+0x25a/0xdd0 net/ipv4/af_inet.c:684 inet_stream_connect+0x66/0xa0 net/ipv4/af_inet.c:755 kernel_connect+0x141/0x1c0 net/socket.c:3740 rds_tcp_conn_path_connect+0x6f6/0x930 net/rds/tcp_connect.c:205 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 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: 11798 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 15402 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)