ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18287/1:b..l rcu: (detected by 0, t=10503 jiffies, g=102281, q=95725 ncpus=2) task:syz-executor state:R running task stack:21872 pid:18287 tgid:18287 ppid:18274 task_flags:0x400140 flags:0x00080000 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:539 [inline] irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 a1 8f 05 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0b 7a 96 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 18 dd 91 RSP: 0018:ffffc90005116c98 EFLAGS: 00000282 RAX: b39fa079616a1300 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000eb4e641d RSI: ffffffff8e215f4f RDI: ffffffff8c28b6e0 RBP: ffffffff8176e256 R08: ffffffff8176e256 R09: ffffffff8e95cca0 R10: ffffc90005116df8 R11: ffffffff81b0e0e0 R12: 0000000000000002 R13: ffffffff8e95cca0 R14: 0000000000000000 R15: 0000000000000246 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 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0xc1c/0xd30 mm/page_alloc.c:2938 __slab_free+0x274/0x2c0 mm/slub.c:5613 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4906 ptlock_alloc+0x20/0x70 mm/memory.c:7579 ptlock_init include/linux/mm.h:3741 [inline] pagetable_pte_ctor include/linux/mm.h:3790 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:79 [inline] pte_alloc_one+0x7a/0x370 arch/x86/mm/pgtable.c:18 __pte_alloc+0x25/0x1a0 mm/memory.c:453 copy_pte_range mm/memory.c:1253 [inline] copy_pmd_range+0x5135/0x5970 mm/memory.c:1408 copy_pud_range mm/memory.c:1445 [inline] copy_p4d_range mm/memory.c:1469 [inline] copy_page_range+0xc13/0x1220 mm/memory.c:1555 dup_mmap+0xf4e/0x1da0 mm/mmap.c:1840 dup_mm kernel/fork.c:1534 [inline] copy_mm+0x13b/0x4a0 kernel/fork.c:1586 copy_process+0x1f1c/0x4440 kernel/fork.c:2264 kernel_clone+0x2d7/0x940 kernel/fork.c:2722 __do_sys_clone kernel/fork.c:2863 [inline] __se_sys_clone kernel/fork.c:2847 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2847 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: 0033:0x7f95e63c58d2 RSP: 002b:00007fffcc47c070 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fffcc47c070 RCX: 00007f95e63c58d2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007fffcc47c1fc R08: 0000000000000000 R09: 0000000000000001 R10: 00005555933bd7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 0000000000070234 R15: 00007fffcc47c250 rcu: rcu_preempt kthread starved for 621 jiffies! g102281 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:27544 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: 18811 Comm: kworker/u8:40 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: krds_cp_wq#5/5 rds_connect_worker RIP: 0010:__sanitizer_cov_trace_switch+0x101/0x130 kernel/kcov.c:-1 Code: 48 c1 e3 05 4c 8d 63 28 4d 39 fc 77 9d 49 ff c6 4d 89 33 49 89 4c 1b 08 4d 89 54 1b 10 49 89 7c 1b 18 49 89 54 1b 20 eb 81 5b <41> 5c 41 5e 41 5f c3 cc cc cc cc cc b9 05 00 00 00 48 85 c0 0f 85 RSP: 0018:ffffc90000a07f70 EFLAGS: 00000246 RAX: 0000000000000004 RBX: 0000000000000001 RCX: 0000000000000001 RDX: ffffffff89c65d3a RSI: ffffffff8fe41600 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffff88804e358000 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000100 R12: 0000000000000000 R13: ffff8880293f8f08 R14: 1ffff1100527f1e0 R15: ffff8880293f8f10 FS: 0000000000000000(0000) GS:ffff88812539e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555c90c4e8 CR3: 000000000e74a000 CR4: 00000000003526f0 Call Trace: nf_hook_slow+0xda/0x220 net/netfilter/core.c:620 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x560/0x6e0 include/linux/netfilter.h:316 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 br_handle_frame_finish+0x14c5/0x1c80 net/bridge/br_input.c:231 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:-1 [inline] br_nf_pre_routing_finish+0x13d7/0x1a90 net/bridge/br_netfilter_hooks.c:430 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_pre_routing+0xed5/0x14c0 net/bridge/br_netfilter_hooks.c:539 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 lock_sock include/net/sock.h:1713 [inline] __inet6_bind+0x30c/0xf60 net/ipv6/af_inet6.c:292 kernel_bind+0x13e/0x1c0 net/socket.c:3660 rds_tcp_conn_path_connect+0x53e/0x930 net/rds/tcp_connect.c:175 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: 68228 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! net_ratelimit: 76162 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge! bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:1b advertised our address fe80::a8aa:aaff:feaa:aa1b on veth0_to_bridge!