rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=30081, q=280 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294968864-4294958362), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g30081 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 rcu: Possible timer handling issue on cpu=1 timer-softirq=14360 rcu: rcu_preempt kthread starved for 10502 jiffies! g30081 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->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 stack:29168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7322 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 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 05/09/2026 RIP: 0010:check_preemption_disabled+0x0/0xe0 lib/smp_processor_id.c:13 Code: c0 75 0f 65 8b 05 1c 98 7f 08 85 c0 74 04 90 0f 0b 90 e9 53 fc ff ff 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 54 55 53 48 83 ec 08 65 8b 1d f5 55 7f 08 65 f7 05 e6 55 7f 08 RSP: 0018:ffffc90000a08d70 EFLAGS: 00000087 RAX: 0000000000000001 RBX: ffff88802d1122c0 RCX: ffffffff899d4e8d RDX: 1ffff11005a2245d RSI: ffffffff8c1ce980 RDI: ffffffff8c1ce9c0 RBP: ffffffff899e0702 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffffc90000a08ff8 R12: 0000000000000000 R13: 18b9eea4b35af1f1 R14: ffff8880343b0c00 R15: ffff8880343b0c00 FS: 0000000000000000(0000) GS:ffff88812445f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000340 CR3: 0000000033ab6000 CR4: 00000000003526f0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:752 trace_lock_release include/trace/events/lock.h:68 [inline] lock_release+0x24d/0x310 kernel/locking/lockdep.c:5879 __raw_spin_unlock include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] advance_sched+0x6a2/0xd20 net/sched/sch_taprio.c:988 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: c6 90 02 e9 c3 48 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 83 e6 1e 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:ffffc90000197e00 EFLAGS: 00000246 RAX: 00000000015fbf9c RBX: ffff88801e2c2540 RCX: ffffffff8b8cb2b5 RDX: 0000000000000001 RSI: ffffffff8c1ce980 RDI: ffffffff81de1ea7 RBP: ffffed1003c584a8 R08: 0000000000000000 R09: ffffed10170a678d R10: ffff8880b8533c6b R11: ffffffff81d4f52c R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff92000032fc4 R15: dffffc0000000000 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+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x158