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): P5286/1:b..l P6648/3:b..l rcu: (detected by 0, t=10503 jiffies, g=156533, q=932 ncpus=2) task:kworker/u8:14 state:R running task stack:22728 pid:6648 tgid:6648 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: krds_cp_wq#17/0 rds_send_worker Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0xe1/0x130 kernel/softirq.c:457 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:914 [inline] __dev_queue_xmit+0x1ed7/0x37f0 net/core/dev.c:4907 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x337/0x540 net/ipv6/ip6_output.c:246 dst_output include/net/dst.h:471 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] ip6_xmit+0x117f/0x1a60 net/ipv6/ip6_output.c:379 inet6_csk_xmit+0x397/0x660 net/ipv6/inet6_connection_sock.c:121 __tcp_transmit_skb+0x2640/0x47c0 net/ipv4/tcp_output.c:1717 tcp_validate_incoming+0x1483/0x2440 net/ipv4/tcp_input.c:6350 tcp_rcv_established+0xc29/0x2910 net/ipv4/tcp_input.c:6642 tcp_v6_do_rcv+0x88a/0x1c70 net/ipv6/tcp_ipv6.c:1625 sk_backlog_rcv include/net/sock.h:1191 [inline] __release_sock+0x1de/0x390 net/core/sock.c:3258 release_sock+0x190/0x260 net/core/sock.c:3857 rds_send_xmit+0x2068/0x28a0 net/rds/send.c:480 rds_send_worker+0x7d/0x2e0 net/rds/threads.c:200 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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 task:dhcpcd state:R running task stack:25312 pid:5286 tgid:5286 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:5945 Code: 1a 00 00 b8 ff ff ff ff 65 0f c1 05 b4 1c 8c 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 48 c7 RSP: 0018:ffffc9000360f290 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8e25a937 RDI: ffffffff8c2a9f80 RBP: 00000000ffffffff R08: ffffffff823fab5a R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8e959c20 R12: 0000000000000246 R13: ffff888029183e00 R14: ffffffff8e959c20 R15: 0000000000000001 lookup_page_ext mm/page_ext.c:258 [inline] page_ext_lookup+0xe7/0x180 mm/page_ext.c:513 page_ext_iter_begin include/linux/page_ext.h:133 [inline] __page_table_check_zero+0x135/0x3e0 mm/page_table_check.c:139 page_table_check_free include/linux/page_table_check.h:46 [inline] __free_pages_prepare mm/page_alloc.c:1407 [inline] __free_frozen_pages+0xc2e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5767 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:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] __do_kmalloc_node mm/slub.c:5361 [inline] __kmalloc_node_track_caller_noprof+0x461/0x730 mm/slub.c:5497 kmalloc_reserve net/core/skbuff.c:637 [inline] __alloc_skb+0x2bd/0x7a0 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] alloc_skb_with_frags+0xc6/0x760 net/core/skbuff.c:6769 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:3010 unix_dgram_sendmsg+0x4da/0x17b0 net/unix/af_unix.c:2136 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] sock_write_iter+0x2de/0x3e0 net/socket.c:1241 do_iter_readv_writev+0x612/0x8c0 fs/read_write.c:-1 vfs_writev+0x343/0x990 fs/read_write.c:1058 do_writev+0x154/0x2e0 fs/read_write.c:1104 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: 0033:0x7f6c373ae407 RSP: 002b:00007ffdf0dec6b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f6c37324780 RCX: 00007f6c373ae407 RDX: 0000000000000005 RSI: 00007ffdf0dec710 RDI: 000000000000000a RBP: 00005601eadef6f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005601eadef6f0 R13: 000000000000012c R14: 00000000ffffffff R15: 0000000000000000 rcu: rcu_preempt kthread starved for 9909 jiffies! g156533 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:27736 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6644 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: krds_cp_wq#15/2 rds_connect_worker RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x2e/0xb0 kernel/rcu/tree.c:752 Code: 41 57 41 56 53 65 ff 05 30 53 94 11 e8 fb 94 08 0a 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 27 2a 8e <4c> 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 1c b6 88 00 RSP: 0018:ffffc90000a07730 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000080000302 RDX: 0000000000000000 RSI: ffffffff8c2a9f60 RDI: ffffffff8c2a9f20 RBP: ffffffff868f3c46 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff868f3be0 R12: 0000000000000002 R13: ffffffff8e959c20 R14: ffffffff8e2a27d8 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125326000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc4ea8df80 CR3: 000000007e8d6000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:23 [inline] lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] veth_xmit+0x83/0xe60 drivers/net/veth.c:357 __netdev_start_xmit include/linux/netdevice.h:5400 [inline] netdev_start_xmit include/linux/netdevice.h:5409 [inline] xmit_one net/core/dev.c:3889 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3905 __dev_queue_xmit+0x1435/0x37f0 net/core/dev.c:4872 dev_queue_xmit include/linux/netdevice.h:3446 [inline] br_dev_queue_push_xmit+0x370/0x4b0 net/bridge/br_forward.c:53 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_post_routing+0xa53/0xee0 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+0xa76/0xea0 net/bridge/br_netfilter_hooks.c:667 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_forward_ip+0x7eb/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+0x1175/0x1990 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+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:6093 __netif_receive_skb_one_core net/core/dev.c:6204 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6670 __napi_poll+0xaa/0x330 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7949 handle_softirqs+0x225/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 __inet6_bind+0x386/0xf30 net/ipv6/af_inet6.c:419 kernel_bind+0x13e/0x1c0 net/socket.c:3646 rds_tcp_conn_path_connect+0x53b/0x920 net/rds/tcp_connect.c:175 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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