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): P9245/1:b..l rcu: (detected by 0, t=10503 jiffies, g=170477, q=1630 ncpus=2) task:syz.9.10009 state:R running task stack:26360 pid:9245 tgid:9244 ppid:7925 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:457 nl80211_netlink_notify+0x46b/0x840 net/wireless/nl80211.c:21514 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380 netlink_release+0x1237/0x1ac0 net/netlink/af_netlink.c:761 __sock_release net/socket.c:653 [inline] sock_close+0xc3/0x240 net/socket.c:1446 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6c5/0x2310 kernel/exit.c:973 do_group_exit+0x21c/0x2d0 kernel/exit.c:1114 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1730f8f749 RSP: 002b:00007f1731dc4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffe00 RBX: 00007f17311e5fa0 RCX: 00007f1730f8f749 RDX: 0000000000000010 RSI: 0000200000000000 RDI: 0000000000000005 RBP: 00007f1731013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f17311e6038 R14: 00007f17311e5fa0 R15: 00007ffefc306dc8 rcu: rcu_preempt kthread starved for 580 jiffies! g170477 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:27096 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 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: 6959 Comm: kworker/u8:58 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker RIP: 0010:memcpy_orig+0x41/0x130 arch/x86/lib/memcpy_64.S:79 Code: 8b 06 4c 8b 4e 08 4c 8b 56 10 4c 8b 5e 18 48 8d 76 20 4c 89 07 4c 89 4f 08 4c 89 57 10 4c 89 5f 18 48 8d 7f 20 73 d4 83 c2 20 44 48 01 d6 48 01 d7 48 83 ea 20 0f 1f 00 48 83 ea 20 4c 8b 46 RSP: 0018:ffffc90000a074f0 EFLAGS: 00000007 RAX: ffffffff8df671a8 RBX: ffffffff99867500 RCX: ffffffff81af4c38 RDX: 0000000000000018 RSI: ffffffff8df67190 RDI: ffffffff8df671c8 RBP: 0000000000000000 R08: ffffffff8dd73aa0 R09: ffffffffffffffff R10: 00000243e3655c95 R11: 0000001800745a85 R12: 0000000000000000 R13: ffffffff99867650 R14: ffffffff998676c4 R15: 1ffffffff330ced8 FS: 0000000000000000(0000) GS:ffff8881261b1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe660055ff8 CR3: 000000000dd3a000 CR4: 00000000003526f0 Call Trace: timekeeping_update_from_shadow+0x4f8/0x720 kernel/time/timekeeping.c:736 __timekeeping_advance+0xc7c/0x10d0 kernel/time/timekeeping.c:2363 timekeeping_advance kernel/time/timekeeping.c:2371 [inline] update_wall_time+0x31/0x200 kernel/time/timekeeping.c:2381 tick_sched_do_timer kernel/time/tick-sched.c:253 [inline] tick_nohz_handler+0xf5/0x710 kernel/time/tick-sched.c:312 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x4d0/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:647 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1229 [inline] RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x4e/0x340 kernel/locking/lockdep.c:5831 Code: 48 8b ac 24 98 00 00 00 65 48 8b 05 4c c6 d8 10 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 4f c6 d8 10 83 f8 08 0f 83 af 01 00 00 <89> c0 48 0f a3 05 78 30 e2 0d 73 0d e8 11 1b 09 00 84 c0 0f 84 d7 RSP: 0018:ffffc90000a07b18 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df41cc0 RBP: ffffffff8173ef25 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000a07cd8 R11: ffffffff81ad4ad0 R12: 0000000000000002 R13: ffffffff8df41cc0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5310 __alloc_skb+0x255/0x430 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] synproxy_send_client_synack_ipv6+0x169/0xca0 net/netfilter/nf_synproxy_core.c:873 nft_synproxy_eval_v6+0x36e/0x560 net/netfilter/nft_synproxy.c:90 nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6137 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6250 process_backlog+0x622/0x1500 net/core/dev.c:6602 __napi_poll+0xae/0x320 net/core/dev.c:7666 napi_poll net/core/dev.c:7729 [inline] net_rx_action+0x672/0xe50 net/core/dev.c:7881 handle_softirqs+0x27d/0x850 kernel/softirq.c:622 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] kernel_fpu_end+0xd2/0x120 arch/x86/kernel/fpu/core.c:480 blake2s_compress+0xe9/0x1b80 lib/crypto/x86/blake2s.h:42 blake2s_final+0x116/0x270 lib/crypto/blake2s.c:148 hmac+0x293/0x330 drivers/net/wireguard/noise.c:333 kdf+0x182/0x270 drivers/net/wireguard/noise.c:375 mix_precomputed_dh drivers/net/wireguard/noise.c:426 [inline] wg_noise_handshake_create_initiation+0x3f1/0x750 drivers/net/wireguard/noise.c:560 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x163/0x320 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246