From ca9a23448caf3d2424f3ad568da3894ed557ba22 Mon Sep 17 00:00:00 2001
From: Ankita Victor-Levi <anvicto@microsoft.com>
Date: Wed, 25 Mar 2026 15:55:54 +0530
Subject: [PATCH] Return defensive copy

---
 .../src/main/java/org/apache/gluten/hash/ConsistentHash.java   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gluten-core/src/main/java/org/apache/gluten/hash/ConsistentHash.java b/gluten-core/src/main/java/org/apache/gluten/hash/ConsistentHash.java
index e3edb34451a0..c94317fe48c6 100644
--- a/gluten-core/src/main/java/org/apache/gluten/hash/ConsistentHash.java
+++ b/gluten-core/src/main/java/org/apache/gluten/hash/ConsistentHash.java
@@ -162,7 +162,8 @@ public Set<T> getNodes() {
   public Set<Partition<T>> getPartition(T node) {
     lock.readLock().lock();
     try {
-      return nodes.get(node);
+      Set<Partition<T>> partitions = nodes.get(node);
+      return partitions == null ? null : Collections.unmodifiableSet(partitions);
     } finally {
       lock.readLock().unlock();
     }