rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14234/1:b..l rcu: (detected by 1, t=10502 jiffies, g=64033, q=1151 ncpus=2) task:syz.4.2253 state:R running task stack:26912 pid:14234 tgid:14224 ppid:5633 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 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:912 [inline] __dev_queue_xmit+0x1fe5/0x3950 net/core/dev.c:4905 dev_queue_xmit include/linux/netdevice.h:3418 [inline] __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline] __netlink_deliver_tap+0x5ad/0x850 net/netlink/af_netlink.c:325 netlink_deliver_tap+0x19c/0x1b0 net/netlink/af_netlink.c:338 netlink_deliver_tap_kernel net/netlink/af_netlink.c:347 [inline] netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x730/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmmsg+0x27c/0x4e0 net/socket.c:2841 __do_sys_sendmmsg net/socket.c:2868 [inline] __se_sys_sendmmsg net/socket.c:2865 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2865 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: 0033:0x7f698179ce59 RSP: 002b:00007f697f9b4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f6981a16180 RCX: 00007f698179ce59 RDX: 040000000000009f RSI: 00002000000002c0 RDI: 0000000000000006 RBP: 00007f6981832d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6981a16218 R14: 00007f6981a16180 R15: 00007ffcfe51c7a8 rcu: rcu_preempt kthread starved for 7749 jiffies! g64033 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: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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8139 Comm: kworker/R-bond1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: bond1 bond_3ad_state_machine_handler RIP: 0010:clear_ti_thread_flag+0x7/0x10 include/linux/thread_info.h:110 Code: 90 90 90 f0 48 83 27 cf c3 cc cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 89 f0 f0 48 0f b3 07 44 8d fb 09 cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900000068e8 EFLAGS: 00000007 RAX: 000000000000000c RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000010100 RSI: 000000000000000c RDI: ffff88802ada9f00 RBP: 0000000000000000 R08: ffffffff903022f7 R09: 1ffffffff206045e R10: dffffc0000000000 R11: fffffbfff206045f R12: 0000000000000000 R13: 0000000000000000 R14: ffffc90000006948 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812529e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8eabb1c7b0 CR3: 0000000077560000 CR4: 00000000003526f0 Call Trace: hrtimer_test_and_clear_rearm_deferred_tif include/linux/hrtimer_rearm.h:20 [inline] hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:52 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline] irqentry_exit+0x870/0x8b0 kernel/entry/common.c:164 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 4d 49 f8 f5 f7 c3 00 02 00 00 74 05 e8 80 e3 23 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 64 c8 e9 f5 65 8b 05 2d 1e 8e 07 85 c0 74 18 5b 41 5e e9 51 48 RSP: 0018:ffffc900000069f0 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000296 RCX: 0000000080000102 RDX: 0000000000000002 RSI: ffffffff8dfa354e RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff903022f7 R09: 1ffffffff206045e R10: dffffc0000000000 R11: fffffbfff206045f R12: ffff8880845a2bb8 R13: ffff8880845a2b00 R14: ffffffff9a706800 R15: 0000000000000001 __debug_check_no_obj_freed lib/debugobjects.c:1135 [inline] debug_check_no_obj_freed+0x52e/0x550 lib/debugobjects.c:1156 slab_free_hook mm/slub.c:2620 [inline] slab_free mm/slub.c:6251 [inline] kmem_cache_free+0xfd/0x650 mm/slub.c:6378 skb_ext_del include/linux/skbuff.h:5101 [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 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 spin_unlock_bh include/linux/spinlock.h:396 [inline] bond_3ad_state_machine_handler+0x5907/0x5bf0 drivers/net/bonding/bond_3ad.c:2597 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 rescuer_thread+0x827/0x1130 kernel/workqueue.c:3621 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: 5361 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) net_ratelimit: 9212 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1) bridge0: received packet on veth1_to_bridge with own address as source address (addr:8e:bd:f1:0e:d8:e9, vlan:1)