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): P27579/1:b..l rcu: (detected by 0, t=10502 jiffies, g=111793, q=276 ncpus=1) task:syz.0.8570 state:R running task stack:27048 pid:27579 tgid:27578 ppid:5823 task_flags:0x40054c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xfe4/0x5e10 kernel/sched/core.c:6867 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7194 irqentry_exit+0x17b/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_lock_acquire include/linux/rcupdate.h:331 [inline] RIP: 0010:rcu_read_lock include/linux/rcupdate.h:867 [inline] RIP: 0010:percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline] RIP: 0010:percpu_ref_put include/linux/percpu-refcount.h:351 [inline] RIP: 0010:css_put include/linux/cgroup_refcnt.h:79 [inline] RIP: 0010:css_put include/linux/cgroup_refcnt.h:76 [inline] RIP: 0010:uncharge_folio+0x541/0x9b0 mm/memcontrol.c:4907 Code: 3c 02 00 0f 85 14 04 00 00 48 c7 43 38 00 00 00 00 e9 20 fe ff ff e8 6e ae 71 ff 31 d2 45 31 c9 45 31 c0 48 8d 05 00 00 00 00 <50> b9 02 00 00 00 31 f6 48 c7 c7 20 31 5e 8e e8 5b 3d 69 ff e8 c6 RSP: 0018:ffffc9000f217458 EFLAGS: 00000246 RAX: ffffffff827948d1 RBX: ffffea0002016b00 RCX: ffffffff827947ca RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888034b24184 RBP: ffffea0002016b00 R08: 0000000000000000 R09: 0000000000000000 R10: ffffea0002016b07 R11: 0000000000000000 R12: ffff88814045a7c0 R13: 0000000000000001 R14: ffffea0002016b38 R15: 0000000000000000 __mem_cgroup_uncharge_folios+0x11b/0x1e0 mm/memcontrol.c:4930 mem_cgroup_uncharge_folios include/linux/memcontrol.h:691 [inline] folios_put_refs+0x52f/0x840 mm/swap.c:1001 free_pages_and_swap_cache+0x242/0x480 mm/swap_state.c:355 __tlb_batch_free_encoded_pages+0xe9/0x280 mm/mmu_gather.c:137 tlb_batch_pages_flush mm/mmu_gather.c:150 [inline] tlb_flush_mmu_free mm/mmu_gather.c:398 [inline] tlb_flush_mmu mm/mmu_gather.c:405 [inline] tlb_finish_mmu+0x1b0/0x810 mm/mmu_gather.c:530 exit_mmap+0x3c5/0xae0 mm/mmap.c:1290 __mmput+0x12a/0x410 kernel/fork.c:1173 mmput+0x67/0x80 kernel/fork.c:1196 exit_mm kernel/exit.c:581 [inline] do_exit+0x78a/0x2a30 kernel/exit.c:959 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034 arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x86/0x4b0 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+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6d6e79aeb9 RSP: 002b:00007f6d6f69f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f6d6ea15fa8 RCX: 00007f6d6e79aeb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6d6ea15fa8 RBP: 00007f6d6ea15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6d6ea16038 R14: 00007ffe31177d00 R15: 00007ffe31177de8 rcu: rcu_preempt kthread starved for 255 jiffies! g111793 f0x0 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:28552 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0xfe4/0x5e10 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0xdd/0x390 kernel/sched/core.c:6964 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x21e/0x320 kernel/rcu/tree.c:2285 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 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: CPU: 0 UID: 0 PID: 3408 Comm: kworker/R-bat_e Tainted: G U I L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:lock_release+0x19e/0x2e0 kernel/locking/lockdep.c:5893 Code: ff 65 0f c1 05 5b 8a 01 12 83 f8 01 0f 85 f7 00 00 00 9c 58 f6 c4 02 0f 85 0c 01 00 00 41 f7 c6 00 02 00 00 0f 85 99 00 00 00 <48> 8b 44 24 10 65 48 2b 05 ed 42 01 12 0f 85 0f 01 00 00 48 83 c4 RSP: 0018:ffffc90000006b58 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e5e3120 RCX: ffffc90000006b64 RDX: 0000000000000004 RSI: ffffffff8dc1b439 RDI: ffffffff8bfa32a0 RBP: ffffffff81b6438e R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000094603 R12: ffff888031d21e80 R13: ffffc90000006c10 R14: 0000000000000206 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e2e532f8c CR3: 00000000628fc000 CR4: 00000000003526f0 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3c3/0x1ea0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 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:2540 [inline] slab_free mm/slub.c:6674 [inline] kmem_cache_free+0x143/0x720 mm/slub.c:6785 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1130 __kfree_skb net/core/skbuff.c:1197 [inline] sk_skb_reason_drop+0x10f/0x1b0 net/core/skbuff.c:1234 kfree_skb_reason include/linux/skbuff.h:1322 [inline] dev_kfree_skb_any_reason net/core/dev.c:3463 [inline] dev_kfree_skb_any_reason+0x79/0x90 net/core/dev.c:3458 dev_kfree_skb_any include/linux/netdevice.h:4194 [inline] team_dummy_transmit+0x1a/0x30 drivers/net/team/team_core.c:503 team_xmit+0x34e/0x460 drivers/net/team/team_core.c:1683 __netdev_start_xmit include/linux/netdevice.h:5273 [inline] netdev_start_xmit include/linux/netdevice.h:5282 [inline] xmit_one net/core/dev.c:3866 [inline] dev_hard_start_xmit+0x127/0x6c0 net/core/dev.c:3882 __dev_queue_xmit+0x6dd/0x46f0 net/core/dev.c:4832 dev_queue_xmit include/linux/netdevice.h:3381 [inline] br_dev_queue_push_xmit+0x587/0x880 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_forward_finish+0x102/0x4d0 net/bridge/br_forward.c:66 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] __br_forward+0x6b1/0x970 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xf0/0x180 net/bridge/br_forward.c:191 br_flood+0x193/0x650 net/bridge/br_forward.c:238 br_handle_frame_finish+0xf57/0x1f00 net/bridge/br_input.c:229 nf_hook_bridge_pre net/bridge/br_input.c:313 [inline] br_handle_frame+0xeec/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0x6d7/0x3460 net/core/dev.c:6039 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6150 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6265 process_backlog+0x37a/0x1580 net/core/dev.c:6617 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7681 napi_poll net/core/dev.c:7744 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7896 handle_softirqs+0x1ea/0x910 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x21c/0x3d0 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x8b/0xbd0 net/batman-adv/translation-table.c:3509 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] rescuer_thread+0x8f1/0xf40 kernel/workqueue.c:3528 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246