From 7cf7cee5a6670209180acd874e84b041da682162 Mon Sep 17 00:00:00 2001
From: TCMalloc Team <tcmalloc-eng@google.com>
Date: Wed, 2 Sep 2026 20:24:16 -0700
Subject: [PATCH] Internal change

PiperOrigin-RevId: 975473070
---
 tcmalloc/internal/numa.h | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/tcmalloc/internal/numa.h b/tcmalloc/internal/numa.h
index db1d7af07..392663119 100644
--- a/tcmalloc/internal/numa.h
+++ b/tcmalloc/internal/numa.h
@@ -236,7 +236,9 @@ inline size_t NumaTopology<NumPartitions, ScaleBy>::GetCurrentPartition()
     const {
   if constexpr (NumPartitions == 1) return 0;
   const int cpu = subtle::percpu::GetRealCpuUnsafe();
-  return gated_cpu_to_scaled_partition_[cpu + kNumaCpuFudge] / ScaleBy;
+  size_t idx = static_cast<size_t>(cpu + kNumaCpuFudge);
+  if (ABSL_PREDICT_FALSE(idx >= kCpuMapSize)) return 0;
+  return gated_cpu_to_scaled_partition_[idx] / ScaleBy;
 }
 
 template <size_t NumPartitions, size_t ScaleBy>
@@ -244,7 +246,9 @@ inline size_t NumaTopology<NumPartitions, ScaleBy>::GetCurrentScaledPartition()
     const {
   if constexpr (NumPartitions == 1) return 0;
   const int cpu = subtle::percpu::GetRealCpuUnsafe();
-  return gated_cpu_to_scaled_partition_[cpu + kNumaCpuFudge];
+  size_t idx = static_cast<size_t>(cpu + kNumaCpuFudge);
+  if (ABSL_PREDICT_FALSE(idx >= kCpuMapSize)) return 0;
+  return gated_cpu_to_scaled_partition_[idx];
 }
 
 template <size_t NumPartitions, size_t ScaleBy>
@@ -256,7 +260,9 @@ inline size_t NumaTopology<NumPartitions, ScaleBy>::GetCpuPartition(
 template <size_t NumPartitions, size_t ScaleBy>
 inline size_t NumaTopology<NumPartitions, ScaleBy>::GetCpuScaledPartition(
     const int cpu) const {
-  return cpu_to_scaled_partition_[cpu + kNumaCpuFudge];
+  size_t idx = static_cast<size_t>(cpu + kNumaCpuFudge);
+  if (ABSL_PREDICT_FALSE(idx >= kCpuMapSize)) return 0;
+  return cpu_to_scaled_partition_[idx];
 }
 
 template <size_t NumPartitions, size_t ScaleBy>