sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=6894/1/0x4000000000000000 softirq=18779/18782 fqs=494 rcu: (detected by 1, t=10505 jiffies, g=12541, q=4464 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6063 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5601 [inline] RIP: 0010:lock_is_held_type+0xaa/0x190 kernel/locking/lockdep.c:5940 Code: 41 83 bd e8 0a 00 00 00 7e 48 4c 89 eb 48 81 c3 f0 0a 00 00 45 31 ff 49 83 ff 31 73 24 48 89 df 4c 89 f6 e8 78 02 00 00 85 c0 <75> 2a 49 ff c7 49 63 85 e8 0a 00 00 48 83 c3 28 49 39 c7 7c d8 eb RSP: 0018:ffffc90000007cf8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff88802c178af0 RCX: 54ff29d7ea65cd00 RDX: ffff88802c178000 RSI: ffff8880b8627a98 RDI: ffff88802c178af0 RBP: 00000000ffffffff R08: ffff88802a384357 R09: ffff88802a384340 R10: dffffc0000000000 R11: ffffed100547086b R12: 0000000000000046 R13: ffff88802c178000 R14: ffff8880b8627a98 R15: 0000000000000000 FS: 00007fbfb9833880(0000) GS:ffff888125c13000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fad411ad988 CR3: 00000000320c4000 CR4: 0000000000350ef0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] __run_hrtimer kernel/time/hrtimer.c:1727 [inline] __hrtimer_run_queues+0x284/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 5b 78 4a f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e3 1e 13 f6 65 8b 05 6c f1 23 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc9000476fc20 EFLAGS: 00000206 RAX: 54ff29d7ea65cd00 RBX: 0000000000000216 RCX: 54ff29d7ea65cd00 RDX: 0000000000000000 RSI: ffffffff8d9ba295 RDI: 0000000000000001 RBP: ffffc9000476fca0 R08: ffffffff8fa3a637 R09: 1ffffffff1f474c6 R10: dffffc0000000000 R11: fffffbfff1f474c7 R12: dffffc0000000000 R13: ffff88801dede500 R14: ffffffff99d8af28 R15: 1ffff920008edf84 __debug_check_no_obj_freed lib/debugobjects.c:1108 [inline] debug_check_no_obj_freed+0x451/0x470 lib/debugobjects.c:1129 slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4695 [inline] kmem_cache_free+0x113/0x400 mm/slub.c:4797 do_sys_openat2+0x154/0x1c0 fs/open.c:1443 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbfb90a7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffdf08f9fc0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fbfb9833880 RCX: 00007fbfb90a7407 RDX: 00000000000a0241 RSI: 00007ffdf08fac80 RDI: ffffffffffffff9c RBP: 0000564aa54a95e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000124 R11: 0000000000000202 R12: 0000564aa543ee00 R13: 00007ffdf08fac80 R14: 00007ffdf08fa880 R15: 00007ffdf08fa480 rcu: rcu_preempt kthread starved for 8035 jiffies! g12541 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:27432 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 6053 Comm: syz-executor.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd31/0x12d0 kernel/smp.c:877 Code: 00 00 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 86 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 31 5f 0b 00 eb 38 90 42 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 RSP: 0018:ffffc900046ff480 EFLAGS: 00000293 RAX: ffffffff81b44e7b RBX: 1ffff110170c8341 RCX: ffff888026fbbc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900046ff600 R08: ffffffff8fa3a637 R09: 1ffffffff1f474c6 R10: dffffc0000000000 R11: fffffbfff1f474c7 R12: ffff8880b8641a08 R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d13000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557aac643138 CR3: 000000000df36000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 exit_mmap+0x44c/0xb50 mm/mmap.c:1293 __mmput+0x118/0x430 kernel/fork.c:1129 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fad4107a693 Code: Unable to access opcode bytes at 0x7fad4107a669. RSP: 002b:00007fffc01875c8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 00000000000017a6 RCX: 00007fad4107a693 RDX: 0000000040000000 RSI: 00007fffc01875dc RDI: 00000000ffffffff RBP: 00007fffc01875dc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fffc0187cb8 R13: 00007fffc0187cb8 R14: 0000000000000001 R15: 00000000fffffff1