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): P5610/1:b..l rcu: (detected by 0, t=10503 jiffies, g=26681, q=769519 ncpus=2) task:syz-executor state:R running task stack:23024 pid:5610 tgid:5610 ppid:5608 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 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+0x205/0x7e0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x19e/0x310 kernel/locking/lockdep.c:5893 Code: ff 65 0f c1 05 db e2 26 12 83 f8 01 0f 85 28 01 00 00 9c 58 f6 c4 02 0f 85 13 01 00 00 41 f7 c6 00 02 00 00 0f 85 c0 00 00 00 <48> 8b 44 24 10 65 48 2b 05 2d 9b 26 12 0f 85 4e 01 00 00 48 83 c4 RSP: 0018:ffffc9000470f508 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e7e5620 RCX: ffffc9000470f514 RDX: 0000000000000002 RSI: ffffffff8defdaa7 RDI: ffffffff8c1c4180 RBP: ffffffff81b7d1ae R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000000aef1 R12: ffff88807d904a00 R13: ffffc9000470f610 R14: 0000000000000202 R15: 0000000000000003 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x3d1/0x7f0 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943 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_kmalloc+0x8a/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827 security_inode_getattr+0x116/0x280 security/security.c:1895 vfs_getattr fs/stat.c:259 [inline] vfs_statx_path fs/stat.c:299 [inline] vfs_statx+0x11f/0x3f0 fs/stat.c:356 vfs_fstatat+0x77/0xe0 fs/stat.c:373 __do_sys_newfstatat+0x9d/0x120 fs/stat.c:538 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f762959b49a RSP: 002b:00007fffb14c24c8 EFLAGS: 00000286 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007f76296321ca RCX: 00007f762959b49a RDX: 00007fffb14c24f0 RSI: 00007fffb14c2580 RDI: 00000000ffffff9c RBP: 00007fffb14c2580 R08: 00007fffb14c3580 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000286 R12: 00007fffb14c3610 R13: 00007f76296321ca R14: 00000000000342b6 R15: 00007fffb14c3650 rcu: rcu_preempt kthread starved for 2907 jiffies! g26681 f0x2 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:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 76 92 02 e9 c3 42 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 81 20 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000246 RAX: 000000000185b1a3 RBX: ffff88801e2ba500 RCX: ffffffff8b8b1095 RDX: 0000000000000000 RSI: ffffffff8df22fb5 RDI: ffffffff8c1c4180 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67b5 R10: ffff8880b8533dab R11: 0000000000000000 R12: 0000000000000001 R13: ffffed1003c574a0 R14: 0000000000000001 R15: ffffffff90d7d650 FS: 0000000000000000(0000) GS:ffff88812446d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff717200218 CR3: 000000002332e000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148