sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29113/1:b..l rcu: (detected by 0, t=10502 jiffies, g=140477, q=1454241 ncpus=2) task:syz-executor state:R running task stack:22808 pid:29113 tgid:29113 ppid:29108 task_flags:0x400140 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:rcu_read_unlock include/linux/rcupdate.h:873 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1183 [inline] RIP: 0010:unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709 Code: a4 0e 01 48 c7 c7 40 a3 c9 8b be 66 03 00 00 48 c7 c2 e0 a3 c9 8b e8 55 4d 2b 00 48 c7 c7 20 9a 95 8e 4c 89 ee e8 d6 33 2b 00 01 e2 34 00 89 e8 48 83 c4 70 5b 41 5c 41 5d 41 5e 41 5f 5d e9 RSP: 0018:ffffc9000348f4a0 EFLAGS: 00000282 RAX: 3f2c9c1764284800 RBX: ffffc9000348f558 RCX: 0000000080000001 RDX: ffffc9000348f501 RSI: ffffffff8c291100 RDI: ffffffff8c2910c0 RBP: 1ffffffff21a7701 R08: ffffc9000348f930 R09: 0000000000000000 R10: ffffc9000348f598 R11: fffff52000691eb5 R12: ffffc90003488000 R13: ffffffff8176a21f R14: ffffc9000348f548 R15: ffffc9000348f940 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: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_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5334 [inline] __kmalloc_noprof+0x358/0x750 mm/slub.c:5347 _kmalloc_noprof include/linux/slab.h:973 [inline] tomoyo_realpath_from_path+0xef/0x640 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827 tomoyo_path_unlink+0xaa/0xf0 security/tomoyo/tomoyo.c:162 security_path_unlink+0x15f/0x330 security/security.c:1483 filename_unlinkat+0x349/0x610 fs/namei.c:5578 __do_sys_unlink fs/namei.c:5616 [inline] __se_sys_unlink+0x2e/0x140 fs/namei.c:5613 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: 0033:0x7f4e07b9bf47 RSP: 002b:00007fff6f02dfa8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4e07b9bf47 RDX: 00007fff6f02dfd0 RSI: 00007fff6f02e060 RDI: 00007fff6f02e060 RBP: 00007fff6f02e060 R08: 00007fff6f02f060 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff6f02f0f0 R13: 00007f4e07c322ca R14: 00000000000a5aa4 R15: 00007fff6f02f130 rcu: rcu_preempt kthread starved for 1361 jiffies! g140477 f0x2 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:28024 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: 0 UID: 0 PID: 10847 Comm: kworker/0:18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker RIP: 0010:__rcu_read_unlock+0x6/0xe0 kernel/rcu/tree_plugin.h:431 Code: 03 38 c1 7c dc 48 89 df e8 67 ab 85 00 eb d2 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d a9 RSP: 0018:ffffc90000006ed0 EFLAGS: 00000282 RAX: 3e8edd44e7cf6b00 RBX: ffffffff90c05cb4 RCX: 0000000080000102 RDX: ffffffff90c05cb0 RSI: ffffffff8c291100 RDI: ffffffff8c2910c0 RBP: 0000000000000000 R08: 0000000000000014 R09: 0000000000000000 R10: ffffc90000006fd8 R11: ffffffff81b10630 R12: dffffc0000000000 R13: ffffffff8176a21f R14: ffffc90000006f88 R15: 1ffff92000000df1 FS: 0000000000000000(0000) GS:ffff88812527c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1e8b2aceb8 CR3: 0000000094ae0000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:873 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x1baf/0x2550 arch/x86/kernel/unwind_orc.c:709 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 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2700 [inline] slab_free mm/slub.c:6310 [inline] kfree+0x1c5/0x640 mm/slub.c:6625 skb_kfree_head net/core/skbuff.c:1077 [inline] skb_free_head net/core/skbuff.c:1089 [inline] skb_release_data+0x85e/0xab0 net/core/skbuff.c:1116 skb_release_all net/core/skbuff.c:1191 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1205 nft_synproxy_eval_v4+0x383/0x530 net/netfilter/nft_synproxy.c:61 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+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:914 [inline] wg_pubkey_hashtable_lookup+0x315/0x360 drivers/net/wireguard/peerlookup.c:69 wg_noise_handshake_consume_initiation+0x3ee/0x9b0 drivers/net/wireguard/noise.c:617 wg_receive_handshake_packet drivers/net/wireguard/receive.c:144 [inline] wg_packet_handshake_receive_worker+0x674/0x10c0 drivers/net/wireguard/receive.c:213 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478 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