rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29 rcu: (detected by 1, t=10502 jiffies, g=137153, q=45118 ncpus=2) task:ktimers/1 state:R running task stack:19808 pid:29 tgid:29 ppid:2 task_flags:0x4208040 flags:0x00080000 Call Trace: sched_show_task+0x49d/0x630 kernel/sched/core.c:7819 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline] print_other_cpu_stall+0xf78/0x1340 kernel/rcu/tree_stall.h:681 check_cpu_stall kernel/rcu/tree_stall.h:856 [inline] rcu_pending kernel/rcu/tree.c:3667 [inline] rcu_sched_clock_irq+0x9a9/0x1140 kernel/rcu/tree.c:2704 update_process_times+0x235/0x2d0 kernel/time/timer.c:2474 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x3e9/0x710 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x4f6/0xd00 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45d/0xa90 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0xa0 kernel/kcov.c:314 Code: 89 74 0a 18 48 89 44 0a 20 e9 c4 ce 15 09 cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 10 b3 91 65 44 8b 05 e7 5e f3 0f 41 81 e0 00 00 RSP: 0018:ffffc90000a3f9e8 EFLAGS: 00000246 RAX: ffffffff88ec1683 RBX: 0000000000000001 RCX: ffff88801bea1e40 RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000100 R10: dffffc0000000000 R11: fffffbfff1db66cf R12: ffff888037800440 R13: ffff888037800000 R14: dffffc0000000000 R15: ffff88803c70a000 advance_sched+0x153/0xc90 net/sched/sch_taprio.c:933 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x542/0xd00 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1858 handle_softirqs+0x1df/0x650 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1138 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: rcu_preempt kthread timer wakeup didn't happen for 4014 jiffies! g137153 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=99059 rcu: rcu_preempt kthread starved for 4015 jiffies! g137153 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27504 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 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+0x510/0xa50 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc 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 23 97 16 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8d207dc0 EFLAGS: 000002c2 RAX: 0000000000948da7 RBX: ffffffff8195d78e RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8ce0c4da RDI: ffffffff8b3f57e0 RBP: ffffffff8d207eb0 R08: ffff8880b8833c5b R09: 1ffff1101710678b R10: dffffc0000000000 R11: ffffed101710678c R12: ffffffff8edb3670 R13: 1ffffffff1a60668 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fadde8998cf CR3: 00000000299ea000 CR4: 00000000003526f0 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:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x381/0x3d0 init/main.c:1206 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