rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P19011/1:b..l P26782/1:b..l rcu: (detected by 1, t=10503 jiffies, g=145889, q=1759 ncpus=2) task:syz.4.5500 state:R running task stack:25400 pid:26782 tgid:26781 ppid:17622 task_flags:0x400140 flags:0x00080002 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/0x760 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 f1 8d 07 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 db d8 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 40 81 0a 0a cc 48 8d 3d 88 7b 92 RSP: 0018:ffffc90003d170d8 EFLAGS: 00000286 RAX: 74428fb9fbce7c00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000ddc393b6 RSI: ffffffff8e22040c RDI: ffffffff8c28b660 RBP: ffffffff8176f256 R08: ffffffff8176f256 R09: ffffffff8e95cca0 R10: ffffc90003d17238 R11: ffffffff81b0f020 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:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 __slab_free+0x274/0x2c0 mm/slub.c:5612 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_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6832 allocate_hook_entries_size net/netfilter/core.c:54 [inline] __nf_hook_entries_try_shrink+0x328/0x700 net/netfilter/core.c:253 __nf_unregister_net_hook+0x4cc/0x6f0 net/netfilter/core.c:513 nf_unregister_net_hook net/netfilter/core.c:-1 [inline] nf_unregister_net_hooks+0xcb/0x140 net/netfilter/core.c:606 nf_ct_netns_do_put net/netfilter/nf_conntrack_proto.c:537 [inline] nf_ct_netns_put+0x36d/0x520 net/netfilter/nf_conntrack_proto.c:-1 cleanup_entry+0x298/0x360 net/ipv6/netfilter/ip6_tables.c:669 translate_table+0x1ecd/0x20b0 net/ipv6/netfilter/ip6_tables.c:744 do_replace net/ipv6/netfilter/ip6_tables.c:1154 [inline] do_ip6t_set_ctl+0x9fe/0xe10 net/ipv6/netfilter/ip6_tables.c:1644 nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2381 __sys_setsockopt net/socket.c:2406 [inline] __do_sys_setsockopt net/socket.c:2412 [inline] __se_sys_setsockopt net/socket.c:2409 [inline] __x64_sys_setsockopt+0x13d/0x1b0 net/socket.c:2409 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4aee79ce59 RSP: 002b:00007f4aec9f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f4aeea15fa0 RCX: 00007f4aee79ce59 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000007 RBP: 00007f4aee832d6f R08: 0000000000000528 R09: 0000000000000000 R10: 0000200000000980 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4aeea16038 R14: 00007f4aeea15fa0 R15: 00007ffc35e769b8 task:syz-executor state:R running task stack:22560 pid:19011 tgid:19011 ppid:1 task_flags:0x40054c 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 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1964 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x3d26/0x4b50 mm/memory.c:2109 unmap_vmas+0x379/0x530 mm/memory.c:2178 exit_mmap+0x280/0x9e0 mm/mmap.c:1300 __mmput+0x118/0x430 kernel/fork.c:1178 exit_mm+0x1f6/0x2d0 kernel/exit.c:582 do_exit+0x6a2/0x22c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f994bd5d68e RSP: 002b:00007fffb51b99f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 0000555569de7500 RCX: 00007f994bd5d68e RDX: 00007fffb51b9a50 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffb51b9abc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000182 R13: 0000000000000061 R14: 00000000000c6cad R15: 00007fffb51b9b10 rcu: rcu_preempt kthread starved for 9869 jiffies! g145889 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:27536 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: CPU: 1 UID: 0 PID: 11617 Comm: kworker/R-bond5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: bond5 bond_alb_monitor RIP: 0010:dev_hard_start_xmit+0x5/0x830 net/core/dev.c:3896 Code: fa ff ff 4c 89 e7 e8 ca 9f b3 f8 e9 93 fa ff ff 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 <41> 57 41 56 41 55 41 54 53 48 81 ec 88 00 00 00 48 89 cb 49 89 d4 RSP: 0018:ffffc90000a077b0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff88806715b980 RCX: ffffc90000a078b8 RDX: ffff88806715b800 RSI: ffff8880544e2000 RDI: ffff88814c3ff8c0 RBP: ffffc90000a07a78 R08: ffff8880530a9ec0 R09: 0000000000000002 R10: 0000000000004888 R11: 0000000000000100 R12: ffff8880544e2000 R13: 0000000100000000 R14: ffff88814c3ff8c0 R15: 1ffff1100ce2b730 FS: 0000000000000000(0000) GS:ffff888125387000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007cdd6000 CR4: 00000000003526f0 Call Trace: __dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870 dev_queue_xmit include/linux/netdevice.h:3418 [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+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 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238 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 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:queue_delayed_work_on+0x17a/0x1e0 kernel/workqueue.c:2617 Code: 00 4d 85 f6 75 16 e8 25 7a 38 00 eb 15 e8 1e 7a 38 00 e8 79 fa 1b 0a 4d 85 f6 74 ea e8 0f 7a 38 00 fb 65 48 8b 05 66 45 ac 11 <48> 3b 44 24 20 75 56 89 d8 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc9000345f920 EFLAGS: 00000293 RAX: cdc389782e245500 RBX: ffff888011f85201 RCX: ffff8880530a9ec0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000008 R08: ffffffff9030d4f7 R09: 1ffffffff2061a9e R10: dffffc0000000000 R11: fffffbfff2061a9f R12: 0000000002000001 R13: 0000000000000000 R14: 0000000000000200 R15: 0000000000000000 queue_delayed_work include/linux/workqueue.h:713 [inline] bond_alb_monitor+0x124e/0x17e0 drivers/net/bonding/bond_alb.c:1628 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