bridge0: received packet on veth1_to_bridge with own address as source address (addr:d6:e5:6a:ea:6f:9c, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2774/1:b..l rcu: (detected by 1, t=10503 jiffies, g=185605, q=1244 ncpus=2) task:syz.0.7911 state:R running task stack:28808 pid:2774 tgid:2765 ppid:26985 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_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 41 30 2c 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 2b 3b ca 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 10 31 2f 0a cc 48 8d 3d 78 d4 b8 RSP: 0018:ffffc9000d257720 EFLAGS: 00000282 RAX: 71ccc9f2c7614900 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 0000000041ab91b9 RSI: ffffffff8e4ae78c RDI: ffffffff8c4bd280 RBP: ffffffff8176f21f R08: ffffffff8176f21f R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c20 R12: 0000000000000002 R13: ffffffff8eb59c20 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xac/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:1406 [inline] __free_frozen_pages+0xc1e/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] kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4959 create_nsproxy kernel/nsproxy.c:58 [inline] create_new_namespaces+0x33/0x6b0 kernel/nsproxy.c:95 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234 ksys_unshare+0x57d/0xa00 kernel/fork.c:3268 __do_sys_unshare kernel/fork.c:3342 [inline] __se_sys_unshare kernel/fork.c:3340 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3340 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: 0033:0x7fe1f519de59 RSP: 002b:00007fe1f5f93028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007fe1f5426180 RCX: 00007fe1f519de59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000028000600 RBP: 00007fe1f5233e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe1f5426218 R14: 00007fe1f5426180 R15: 00007ffe3eb66888 rcu: rcu_preempt kthread starved for 602 jiffies! g185605 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:27496 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 48 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: krds_cp_wq#16/5 rds_connect_worker RIP: 0010:skb_zcopy_managed include/linux/skbuff.h:1805 [inline] RIP: 0010:skb_zcopy_downgrade_managed include/linux/skbuff.h:1886 [inline] RIP: 0010:pskb_expand_head+0xef/0x13a0 net/core/skbuff.c:2301 Code: 3c 18 00 74 08 4c 89 f7 e8 be 4b 9a f8 4d 8b 3e 48 8b 44 24 28 0f b6 04 18 84 c0 0f 85 45 0e 00 00 48 8b 04 24 8b 00 49 01 c7 <4c> 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 49 0e 00 00 4c 89 74 RSP: 0018:ffffc90000006d70 EFLAGS: 00000282 RAX: 0000000000000180 RBX: dffffc0000000000 RCX: 0000000000000100 RDX: ffff88801fe80000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 0000000000000100 R08: ffff8881ab7c5367 R09: 1ffff110356f8a6c R10: dffffc0000000000 R11: ffffed10356f8a6d R12: 0000000000000820 R13: 0000000000000000 R14: ffff8881ab7c5350 R15: ffff888041704e80 FS: 0000000000000000(0000) GS:ffff888124f5a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fda15494caa CR3: 0000000021bdc000 CR4: 00000000003526f0 Call Trace: netif_skb_check_for_xdp net/core/dev.c:5571 [inline] netif_receive_generic_xdp net/core/dev.c:5602 [inline] do_xdp_generic+0x9a5/0x12d0 net/core/dev.c:5670 __netif_receive_skb_core+0x10e0/0x30b0 net/core/dev.c:6016 __netif_receive_skb_one_core net/core/dev.c:6204 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] netif_receive_skb_internal net/core/dev.c:6405 [inline] netif_receive_skb+0x1fe/0xbf0 net/core/dev.c:6464 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: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 net_ratelimit: 13766 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:1c, 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:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:d6:e5:6a:ea:6f:9c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, 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:1c, 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:1c, vlan:0) net_ratelimit: 18109 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:d6:e5:6a:ea:6f:9c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, 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:1c, 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:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:d6:e5:6a:ea:6f:9c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)