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): P5866/1:b..l rcu: (detected by 0, t=10606 jiffies, g=9053, q=528 ncpus=2) task:udevd state:R running task stack:26344 pid:5866 tgid:5866 ppid:5184 task_flags:0x40014c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256 irqentry_exit+0x36/0x90 kernel/entry/common.c:211 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: e6 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 22 54 e9 0e 0f 82 74 02 00 00 8b 35 9a 84 e9 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 e6 08 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90003077560 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c4760 RCX: 00000000dbfb52df RDX: 0000000000000000 RSI: ffffffff8da06f71 RDI: ffffffff8bf07440 RBP: 0000000000000002 R08: 11edc8a8be3b5a24 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 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+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:559 slab_free_hook mm/slub.c:2504 [inline] slab_free mm/slub.c:6642 [inline] kmem_cache_free+0x15e/0x6c0 mm/slub.c:6752 anon_vma_free mm/rmap.c:136 [inline] __put_anon_vma+0x114/0x3a0 mm/rmap.c:2777 put_anon_vma include/linux/rmap.h:117 [inline] unlink_anon_vmas+0x58a/0x820 mm/rmap.c:443 free_pgtables+0x212/0xc00 mm/memory.c:414 exit_mmap+0x3f4/0xb90 mm/mmap.c:1291 __mmput+0x12a/0x410 kernel/fork.c:1133 mmput+0x62/0x70 kernel/fork.c:1156 exit_mm kernel/exit.c:582 [inline] do_exit+0x7c7/0x2bf0 kernel/exit.c:954 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107 __do_sys_exit_group kernel/exit.c:1118 [inline] __se_sys_exit_group kernel/exit.c:1116 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1116 x64_sys_call+0x150b/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d2a0f16c5 RSP: 002b:00007ffec6cb4218 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000562a8ddf2d90 RCX: 00007f0d2a0f16c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 0000562a8dba32c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffec6cb4260 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10606 jiffies! g9053 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:28136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 767 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__lock_acquire+0x1b0/0x1c90 kernel/locking/lockdep.c:5174 Code: 49 89 45 08 48 8b 44 24 08 49 89 45 18 8b b5 14 0b 00 00 31 c0 65 8b 15 d6 48 09 12 85 f6 0f 95 c0 85 d2 0f 95 c2 41 c1 e6 0f e1 10 0f b6 d2 45 0f b7 f6 41 c1 e0 13 8d 04 50 8b 14 24 81 e1 RSP: 0018:ffffc90000a08c50 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000000002 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffff888025728000 R08: 0000000000000001 R09: 0000000000000001 R10: 00000000000000c8 R11: 0000000000000001 R12: ffff888025728b30 R13: ffff888025728bf8 R14: 0000000000000000 R15: ffffffff8e3c4760 FS: 0000000000000000(0000) GS:ffff888124b05000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562a8ddddbe0 CR3: 0000000071911000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] advance_sched+0x699/0xc80 net/sched/sch_taprio.c:990 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: e6 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 22 54 e9 0e 0f 82 74 02 00 00 8b 35 9a 84 e9 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 e6 08 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90002fb6a70 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c4760 RCX: 00000000dcf14873 RDX: 0000000000000000 RSI: ffffffff8da06f71 RDI: ffffffff8bf07440 RBP: 0000000000000002 R08: 64354bf8f0b062d9 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 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+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5650 [inline] __kmalloc_noprof+0x32f/0x880 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ieee802_11_parse_elems_full+0x1db/0x3780 net/mac80211/parse.c:1011 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2470 [inline] ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2477 [inline] ieee80211_inform_bss+0x10b/0x1140 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0x8ea/0x1df0 net/wireless/scan.c:2385 cfg80211_inform_bss_data+0x22b/0x3be0 net/wireless/scan.c:3240 cfg80211_inform_bss_frame_data+0x26f/0x750 net/wireless/scan.c:3331 ieee80211_bss_info_update+0x310/0xab0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline] ieee80211_ibss_rx_queued_mgmt+0x191b/0x2fe0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1702 [inline] ieee80211_iface_work+0xe2e/0x1360 net/mac80211/iface.c:1756 cfg80211_wiphy_work+0x2c7/0x580 net/wireless/core.c:435 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245