rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=94937, q=724 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 5500 (4295002300-4294996800), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 5501 jiffies! g94937 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:27968 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] schedule+0x164/0x360 kernel/sched/core.c:7277 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+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: 20001 Comm: kworker/R-bond4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: bond4 bond_alb_monitor RIP: 0010:rps_input_queue_tail_save include/net/rps.h:181 [inline] RIP: 0010:enqueue_to_backlog+0x6be/0xee0 net/core/dev.c:5410 Code: 89 da e8 75 8e f7 ff b8 01 00 00 00 eb 33 e8 09 cb 45 f8 e8 44 82 33 02 4d 85 f6 0f 84 84 fd ff ff e8 f6 ca 45 f8 fb 4c 89 e0 <48> c1 e8 03 42 0f b6 04 28 84 c0 0f 85 90 04 00 00 41 89 1c 24 31 RSP: 0018:ffffc90000a07db0 EFLAGS: 00000246 RAX: ffffc90000a07e58 RBX: 00000000001ddfc3 RCX: ffff88806bcebd80 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880b873cba0 R08: ffffffff903215b7 R09: 1ffffffff20642b6 R10: dffffc0000000000 R11: fffffbfff20642b7 R12: ffffc90000a07e58 R13: dffffc0000000000 R14: 0000000000000200 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125345000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005585fc037d08 CR3: 00000000797b2000 CR4: 00000000003526f0 Call Trace: netif_rx_internal+0x120/0x560 net/core/dev.c:5719 __netif_rx+0x78/0xc0 net/core/dev.c:5739 veth_forward_skb drivers/net/veth.c:325 [inline] veth_xmit+0x587/0xdb0 drivers/net/veth.c:379 __netdev_start_xmit include/linux/netdevice.h:5343 [inline] netdev_start_xmit include/linux/netdevice.h:5352 [inline] xmit_one net/core/dev.c:3888 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904 __dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870 dev_queue_xmit include/linux/netdevice.h:3401 [inline] br_dev_queue_push_xmit+0x370/0x4b0 net/bridge/br_forward.c:53 NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:318 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:318 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 br_handle_frame_finish+0x1521/0x1c80 net/bridge/br_input.c:229 nf_hook_bridge_pre net/bridge/br_input.c:313 [inline] br_handle_frame+0x80f/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6096 __netif_receive_skb_one_core net/core/dev.c:6207 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6673 __napi_poll+0xae/0x340 net/core/dev.c:7737 napi_poll net/core/dev.c:7800 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7957 handle_softirqs+0x22a/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:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 0d 5c ec f5 f7 c3 00 02 00 00 74 05 e8 10 78 17 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 a4 ed dd f5 65 8b 05 9d f0 87 07 85 c0 74 18 5b 41 5e e9 41 48 RSP: 0018:ffffc90005cef500 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000202 RCX: 0000000080000001 RDX: 0000000000000006 RSI: ffffffff8dfb6703 RDI: 0000000000000001 RBP: ffff888140410c48 R08: ffffffff903215b7 R09: 1ffffffff20642b6 R10: dffffc0000000000 R11: fffffbfff20642b7 R12: ffffea0005477810 R13: ffffea0005473010 R14: ffff888140410c00 R15: 0000000000000009 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] alloc_from_new_slab+0x1b1/0x240 mm/slub.c:4360 refill_objects+0x358/0x3c0 mm/slub.c:7185 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] kmem_cache_alloc_node_noprof+0x441/0x690 mm/slub.c:4918 kmalloc_reserve net/core/skbuff.c:613 [inline] __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713 __netdev_alloc_skb+0xc1/0x810 net/core/skbuff.c:775 netdev_alloc_skb include/linux/skbuff.h:3499 [inline] dev_alloc_skb include/linux/skbuff.h:3512 [inline] alb_send_lp_vid+0x122/0x550 drivers/net/bonding/bond_alb.c:931 alb_send_learning_packets+0x12c/0x300 drivers/net/bonding/bond_alb.c:1012 bond_alb_monitor+0x3d5/0x17e0 drivers/net/bonding/bond_alb.c:1563 process_one_work kernel/workqueue.c:3288 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371 rescuer_thread+0x827/0x1130 kernel/workqueue.c:3595 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 bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)