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): P19313/1:b..l rcu: (detected by 0, t=10502 jiffies, g=119473, q=836 ncpus=1) task:syz.2.5565 state:R running task stack:25832 pid:19313 tgid:19312 ppid:16319 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7284 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7606 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa10 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] RIP: 0010:unwind_next_frame+0xcdf/0x2090 arch/x86/kernel/unwind_orc.c:614 Code: 05 4c 89 44 24 18 83 e0 07 3c 03 0f 84 cc 03 00 00 3c 04 0f 84 05 03 00 00 48 89 4c 24 20 3c 02 0f 85 60 f6 ff ff 49 8d 76 f8 08 00 00 00 4d 8d 7d 34 4c 89 ef 48 89 74 24 28 e8 2b f1 ff ff RSP: 0018:ffffc90004e6f390 EFLAGS: 00000246 RAX: 0000000000000002 RBX: 0000000000000001 RCX: ffffffff91f62ac6 RDX: 0000000000000000 RSI: ffffc90004e6f6f8 RDI: 0000000000000001 RBP: ffffc90004e6f448 R08: ffffffff91f62aca R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000017072 R12: ffffc90004e6f450 R13: ffffc90004e6f400 R14: ffffc90004e6f700 R15: ffffc90004e6f680 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:183 __reset_page_owner+0x84/0x190 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_node_track_caller_noprof+0x2da/0x870 mm/slub.c:5545 kmemdup_noprof+0x29/0x60 mm/util.c:138 kmemdup_noprof include/linux/fortify-string.h:715 [inline] scm_fp_dup+0x63/0x410 net/core/scm.c:438 unix_peek_fds net/unix/af_unix.c:1967 [inline] __unix_dgram_recvmsg+0x9b1/0xc30 net/unix/af_unix.c:2665 unix_dgram_recvmsg+0xcd/0x100 net/unix/af_unix.c:2689 sock_recvmsg_nosec net/socket.c:1151 [inline] ____sys_recvmsg+0x5eb/0x670 net/socket.c:2931 ___sys_recvmsg+0x16a/0x1a0 net/socket.c:2975 do_recvmmsg+0x2f3/0x740 net/socket.c:3070 __sys_recvmmsg net/socket.c:3144 [inline] __do_sys_recvmmsg net/socket.c:3167 [inline] __se_sys_recvmmsg net/socket.c:3160 [inline] __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3160 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f8659e159 RSP: 002b:00007f8f87548028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f8f86825fa0 RCX: 00007f8f8659e159 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f8f8663506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8f86826038 R14: 00007f8f86825fa0 R15: 00007ffffc0a4e38 rcu: rcu_preempt kthread starved for 866 jiffies! g119473 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:28984 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7376 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x8f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x17a/0x220 kernel/rcu/tree.c:2330 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: 3224 Comm: kworker/R-bat_e Tainted: G S L syzkaller #0 PREEMPT(full) Tainted: [S]=CPU_OUT_OF_SPEC, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:unwind_get_return_address+0x72/0xa0 arch/x86/kernel/unwind_orc.c:385 Code: ea 03 80 3c 02 00 75 36 48 8b 7b 48 e8 67 dd 18 00 85 c0 74 cf 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 <75> 1c 48 8b 43 48 5b 5d c3 cc cc cc cc e8 ac c7 c5 00 eb a0 48 89 RSP: 0018:ffffc900000071c0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc900000071d8 RCX: ffffc9000000712c RDX: 1ffff92000000e44 RSI: ffffffff8e366aae RDI: ffffffff827f3804 RBP: ffffc90000007220 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000017f37 R12: ffffffff81f5ef20 R13: ffffc90000007298 R14: 0000000000000000 R15: ffff88803447a580 FS: 0000000000000000(0000) GS:ffff888123b53000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff27fc08622 CR3: 0000000075871000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0xa6/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6508 [inline] kmem_cache_free+0x127/0x6c0 mm/slub.c:6635 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1145 __kfree_skb net/core/skbuff.c:1212 [inline] consume_skb net/core/skbuff.c:1448 [inline] consume_skb+0xd1/0x110 net/core/skbuff.c:1442 nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:91 [inline] nft_synproxy_do_eval+0x919/0xce0 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e5/0x19d0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:280 NF_HOOK include/linux/netfilter.h:323 [inline] ip6_input+0xe0/0x2f0 net/ipv6/ip6_input.c:545 dst_input include/net/dst.h:480 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:119 [inline] NF_HOOK include/linux/netfilter.h:325 [inline] NF_HOOK include/linux/netfilter.h:319 [inline] ipv6_rcv+0x263/0x3d0 net/ipv6/ip6_input.c:351 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6264 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6377 process_backlog+0x487/0x1600 net/core/dev.c:6728 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7787 napi_poll net/core/dev.c:7850 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:8007 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645 do_softirq kernel/softirq.c:546 [inline] do_softirq+0xaf/0xf0 kernel/softirq.c:533 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473 spin_unlock_bh include/linux/spinlock.h:407 [inline] batadv_tt_local_purge+0x21c/0x3d0 net/batman-adv/translation-table.c:1402 batadv_tt_purge+0x8b/0xbd0 net/batman-adv/translation-table.c:3753 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] rescuer_thread+0x918/0x14e0 kernel/workqueue.c:3703 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245