rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20834/1:b..l rcu: (detected by 1, t=10502 jiffies, g=409017, q=1573 ncpus=2) task:syz.2.21652 state:R running task stack:25144 pid:20834 tgid:20833 ppid:15592 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552 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:kasan_check_range+0x1ca/0x2c0 mm/kasan/generic.c:200 Code: dc 4d 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 0e 41 80 3b 00 75 7c 49 ff c3 49 ff cc 75 f2 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 45 84 ff 0f 85 a1 00 00 00 RSP: 0018:ffffc900078b7a80 EFLAGS: 00000256 RAX: ffffffff823b0a01 RBX: 0000000000000008 RCX: ffffffff823b0aa1 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88801ed5b3f0 RBP: ffff88801ed5b3f8 R08: ffff88801ed5b3f7 R09: 1ffff11003dab67e R10: dffffc0000000000 R11: ffffed1003dab67f R12: 0000000000084571 R13: dffffc0000000000 R14: ffffed1003dab67f R15: 1ffff11003dab67e instrument_write include/linux/instrumented.h:41 [inline] ___clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:44 [inline] __update_page_owner_free_handle+0x1b1/0x470 mm/page_owner.c:288 __reset_page_owner+0x85/0x1f0 mm/page_owner.c:321 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938 __slab_free+0x274/0x2c0 mm/slub.c:5672 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:4610 [inline] slab_alloc_node mm/slub.c:4939 [inline] kmem_cache_alloc_noprof+0x2b8/0x650 mm/slub.c:4946 alloc_empty_file+0x5b/0x1d0 fs/file_table.c:262 alloc_file fs/file_table.c:396 [inline] alloc_file_pseudo+0x115/0x1e0 fs/file_table.c:427 sock_alloc_file+0xb8/0x2e0 net/socket.c:532 sock_map_fd net/socket.c:562 [inline] __sys_socket+0x13f/0x1b0 net/socket.c:1802 __do_sys_socket net/socket.c:1807 [inline] __se_sys_socket net/socket.c:1805 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1805 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: 0033:0x7f62eb59ce59 RSP: 002b:00007f62ec41d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f62eb815fa0 RCX: 00007f62eb59ce59 RDX: 0000000000000084 RSI: 0000000000000005 RDI: 000000000000000a RBP: 00007f62eb632e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f62eb816038 R14: 00007f62eb815fa0 R15: 00007ffd6484ae48 rcu: rcu_preempt kthread starved for 7723 jiffies! g409017 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:28056 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 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: CPU: 1 UID: 0 PID: 8293 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: 0x0 (bond1) 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 9d da f7 f5 f7 c3 00 02 00 00 74 05 e8 10 97 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 e4 f1 e8 f5 65 8b 05 2d b4 8f 07 85 c0 74 18 5b 41 5e e9 91 48 RSP: 0018:ffffc90000a07cb0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000246 RCX: 0000000080000105 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: 0000000000000001 RBP: ffff8880b8741200 R08: ffffffff903117f7 R09: 1ffffffff20622fe R10: dffffc0000000000 R11: fffffbfff20622ff R12: ffff8880b8741280 R13: 0000000000000002 R14: ffff88823fff8700 R15: 0000000000000801 FS: 0000000000000000(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000080 CR3: 000000007fd1c000 CR4: 00000000003526f0 Call Trace: spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] rmqueue_bulk mm/page_alloc.c:2543 [inline] __rmqueue_pcplist+0x1332/0x1c70 mm/page_alloc.c:3329 rmqueue_pcplist mm/page_alloc.c:3367 [inline] rmqueue mm/page_alloc.c:3397 [inline] get_page_from_freelist+0x9c1/0x2530 mm/page_alloc.c:3938 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab+0x74/0x5d0 mm/slub.c:3404 new_slab mm/slub.c:3447 [inline] refill_objects+0x328/0x3c0 mm/slub.c:7241 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x2e0/0x6b0 mm/slub.c:4692 alloc_from_pcs mm/slub.c:4790 [inline] slab_alloc_node mm/slub.c:4924 [inline] kmem_cache_alloc_node_noprof+0x437/0x680 mm/slub.c:4991 kmalloc_reserve net/core/skbuff.c:615 [inline] __alloc_skb+0x276/0x7a0 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1386 [inline] synproxy_send_client_synack+0x175/0xde0 net/netfilter/nf_synproxy_core.c:463 nft_synproxy_eval_v4+0x37b/0x530 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x335/0x550 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x48d/0x1b10 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:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0xa34/0x1860 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 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:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:native_irq_enable arch/x86/include/asm/irqflags.h:-1 [inline] RIP: 0010:arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline] RIP: 0010:raw_spin_rq_unlock_irq kernel/sched/sched.h:1673 [inline] RIP: 0010:__schedule+0x1da2/0x56c0 kernel/sched/core.c:7233 Code: 31 f6 e8 01 cb eb f5 4c 89 ff e8 a9 d7 ec f5 0f 1f 44 00 00 49 83 c7 48 4c 89 ff e8 78 c1 01 00 e8 13 59 25 f6 fb 4c 8b 24 24 3a fa ff ff 90 0f 0b 90 f7 c6 01 01 00 00 0f 85 2a e8 ff ff e9 RSP: 0018:ffffc90003e1fac0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 1ffff920007c3f7c RCX: 0000000080000002 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: ffffffff8ba8c9dd RBP: ffffc90003e1fca8 R08: ffffffff903117f7 R09: 1ffffffff20622fe R10: dffffc0000000000 R11: fffffbfff20622ff R12: ffff888030ee1f00 R13: dffffc0000000000 R14: ffff888030ee1f00 R15: ffff8880b873afc8 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 rescuer_thread+0xf45/0x10b0 kernel/workqueue.c:3670 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 GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog