rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9507/1:b..l rcu: (detected by 0, t=10503 jiffies, g=50745, q=1033700 ncpus=2) task:syz.4.1134 state:R running task stack:26168 pid:9507 tgid:9501 ppid:5641 task_flags:0x40054c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__kasan_check_byte+0x2c/0x40 mm/kasan/common.c:578 Code: 40 d6 41 56 53 48 89 f3 49 89 fe e8 3e 15 00 00 84 c0 75 16 be 01 00 00 00 4c 89 f7 31 d2 48 89 d9 89 c3 e8 f6 04 00 00 89 d8 <5b> 41 5e e9 4c 6a 7a 09 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 RSP: 0018:ffffc9000534ecc0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff8176e273 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8176e273 RDI: 1ffffffff1d2b9ac RBP: ffffffff8176e256 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc9000534ee98 R11: ffffffff81b0d870 R12: 0000000000000002 R13: ffffffff8e95cd60 R14: ffffffff8e95cd60 R15: 0000000000000000 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5842 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_unref_folios+0xcec/0x1480 mm/page_alloc.c:3004 folios_put_refs+0x9ff/0xb40 mm/swap.c:1008 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x289/0xae0 mm/shmem.c:1407 evict+0x61e/0xb10 fs/inode.c:841 __dentry_kill+0x1a2/0x690 fs/dcache.c:718 finish_dput+0xc9/0x480 fs/dcache.c:927 __fput+0x691/0xa60 fs/file_table.c:518 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:975 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 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:238 [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: 0033:0x7f3aeed9cdd9 RSP: 002b:00007f3aefcb20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f3aef016098 RCX: 00007f3aeed9cdd9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3aef016098 RBP: 00007f3aef016090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3aef016128 R14: 00007f3aef13f960 R15: 00007f3aef13fa48 rcu: rcu_preempt kthread starved for 1379 jiffies! g50745 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8009 Comm: kworker/R-bond5 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: bond5 bond_3ad_state_machine_handler RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:unwind_next_frame+0x1a33/0x2550 arch/x86/kernel/unwind_orc.c:694 Code: 48 8b 7c 24 78 0f 85 54 01 00 00 48 8b 44 24 58 80 3c 28 00 74 05 e8 bc eb b9 00 4d 8b 66 38 49 8d 7e 08 48 89 f8 48 c1 e8 03 <80> 3c 28 00 74 05 e8 a2 eb b9 00 4d 8b 6e 08 4d 8d 7e 10 4c 89 f8 RSP: 0018:ffffc90000a07d78 EFLAGS: 00000a06 RAX: 1ffff92000140fca RBX: ffffffff90d2dd01 RCX: 0000000000000001 RDX: ffffc90000a07e88 RSI: dffffc0000000000 RDI: ffffc90000a07e50 RBP: dffffc0000000000 R08: ffffc90000a081e8 R09: 0000000000000000 R10: ffffc90000a07e98 R11: fffff52000140fd5 R12: ffffc90000a081f8 R13: 1ffff92000140fcb R14: ffffc90000a07e48 R15: ffffffff8176e256 FS: 0000000000000000(0000) GS:ffff888125390000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000031f030 CR3: 000000000e74a000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4950 kmalloc_reserve net/core/skbuff.c:613 [inline] __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] synproxy_send_client_synack+0x172/0xe30 net/netfilter/nf_synproxy_core.c:461 nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x467/0x19f0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 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+0x21f/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6202 [inline] __netif_receive_skb net/core/dev.c:6315 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6666 __napi_poll+0xae/0x340 net/core/dev.c:7730 napi_poll net/core/dev.c:7793 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7950 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:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 rescuer_thread+0x827/0x1130 kernel/workqueue.c:3609 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