sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=27d4/1/0x4000000000000000 softirq=121629/121629 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5933/1:b..l rcu: (detected by 0, t=10506 jiffies, g=110761, q=281 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 21434 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:mark_usage kernel/locking/lockdep.c:4639 [inline] RIP: 0010:__lock_acquire+0x65e/0xd20 kernel/locking/lockdep.c:5191 Code: 00 74 55 48 8b 3c 24 4c 89 f6 ba 05 00 00 00 eb 36 85 c9 74 1d 45 31 ff 48 8b 3c 24 4c 89 f6 31 d2 e8 d6 25 00 00 48 8b 3c 24 <85> c0 0f 84 42 06 00 00 83 bf 14 0b 00 00 00 74 1d 48 8b 3c 24 4c RSP: 0018:ffffc90000a08b70 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000002 RCX: ffffffff93172858 RDX: 0000000000000000 RSI: ffff8880291fe5f0 RDI: ffff8880291fdac0 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ada832 R10: dffffc0000000000 R11: fffffbfff1ef9a8f R12: ffffffffffffff02 R13: 0000000000000002 R14: ffff8880291fe5f0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812623e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000001f000 CR3: 000000005cd3d000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1781 [inline] __hrtimer_run_queues+0x602/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_quarantine_put+0x88/0x220 mm/kasan/quarantine.c:237 Code: e8 3d fb a1 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 88 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f e9 91 78 ea fe cc 48 8d 80 RSP: 0018:ffffc9001430fc88 EFLAGS: 00000206 RAX: d7b78a586cf0e801 RBX: ffff8880319e4800 RCX: d7b78a586cf0e800 RDX: 0000000000000000 RSI: ffffffff8d70bf53 RDI: ffffffff8bbf05e0 RBP: 0000000000000000 R08: ffffffff8f7cd477 R09: 1ffffffff1ef9a8e R10: dffffc0000000000 R11: fffffbfff1ef9a8f R12: ffffea0000c67900 R13: 0000000000000000 R14: 000000000000a798 R15: 0000000000000286 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6740 do_exit+0x677/0x2300 kernel/exit.c:962 do_group_exit+0x21c/0x2d0 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+0x3f/0x40 kernel/exit.c:1116 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7f943196c5 Code: Unable to access opcode bytes at 0x7f7f9431969b. RSP: 002b:00007ffca4cc15a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007ffca4cc1804 RCX: 00007f7f943196c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000003 R08: 00007ffca4cc16a0 R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffca4cc18e0 R14: 00007f7f94529000 R15: 000055e47abcdd98 task:kworker/1:6 state:R running task stack:21912 pid:5933 tgid:5933 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_lock_acquire include/linux/rcupdate.h:331 [inline] RIP: 0010:rcu_read_lock include/linux/rcupdate.h:867 [inline] RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1195 [inline] RIP: 0010:unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479 Code: de 1b 00 00 41 8b 06 85 c0 0f 84 32 02 00 00 89 84 24 84 00 00 00 4c 89 bc 24 90 00 00 00 e8 a2 7a 33 00 4c 8d 3d 00 00 00 00 <48> c7 c7 e0 d2 f3 8d 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 RSP: 0018:ffffc9000495f1d8 EFLAGS: 00000283 RAX: 0000000000000001 RBX: ffffffff8173b5c8 RCX: dffffc0000000000 RDX: ffffc9000495f398 RSI: dffffc0000000000 RDI: ffffc9000495f308 RBP: dffffc0000000000 R08: ffffc9000495f301 R09: ffffc9000495f308 R10: dffffc0000000000 R11: fffff5200092be6d R12: 1ffff9200092be61 R13: ffffc9000495f340 R14: ffffc9000495f308 R15: ffffffff81738d25 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5763 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] usb_alloc_dev+0x5d/0xd00 drivers/usb/core/usb.c:650 hub_port_connect drivers/usb/core/hub.c:5469 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2214/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10506 jiffies! g110761 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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+0x4bc/0x870 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 5e 33 ca f5 cc cc cc 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 33 21 22 00 f3 0f 1e fa fb f4 33 33 ca f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6 RAX: 191287851069e800 RBX: ffffffff81967be7 RCX: 191287851069e800 RDX: 0000000000000001 RSI: ffffffff8d70bf53 RDI: ffffffff8bbf05e0 RBP: ffffffff8dc07ea8 R08: ffff8880b8832fdb R09: 1ffff110171065fb R10: dffffc0000000000 R11: ffffed10171065fc R12: ffffffff8f7cd470 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a40 FS: 0000000000000000(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001540 CR3: 000000004bcce000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147