[Bug] Calling queryMessage rocketmq may pose an OOM risk #7948

Author: yangxiaohui

store/src/main/java/org/apache/rocketmq/store/index/IndexService.java

@@ -164,11 +164,10 @@ public void destroy() {
     }
 
     public QueryOffsetResult queryOffset(String topic, String key, int maxNum, long begin, long end) {
-        List<Long> phyOffsets = new ArrayList<>(maxNum);
-
         long indexLastUpdateTimestamp = 0;
         long indexLastUpdatePhyoffset = 0;
         maxNum = Math.min(maxNum, this.defaultMessageStore.getMessageStoreConfig().getMaxMsgsNumBatch());
+        List<Long> phyOffsets = new ArrayList<>(maxNum);
         try {
             this.readWriteLock.readLock().lock();
             if (!this.indexFileList.isEmpty()) {

store/src/test/java/org/apache/rocketmq/store/index/IndexServiceTest.java

@@ -0,0 +1,32 @@
+package org.apache.rocketmq.store.index;
+
+import org.apache.rocketmq.common.BrokerConfig;
+import org.apache.rocketmq.store.DefaultMessageStore;
+import org.apache.rocketmq.store.config.MessageStoreConfig;
+import org.apache.rocketmq.store.stats.BrokerStatsManager;
+import org.junit.Test;
+
+import java.util.concurrent.ConcurrentHashMap;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
+
+public class IndexServiceTest {
+
+    @Test
+    public void testQueryOffsetThrow() throws Exception {
+        assertDoesNotThrow(() -> {
+            DefaultMessageStore store = new DefaultMessageStore(
+                    new MessageStoreConfig(),
+                    new BrokerStatsManager(new BrokerConfig()),
+                    null,
+                    new BrokerConfig(),
+                    new ConcurrentHashMap<>()
+            );
+
+            IndexService indexService = new IndexService(store);
+            indexService.queryOffset("test", "", Integer.MAX_VALUE, 10, 100);
+        });
+    }
+
+}