From 1d53ac30f1db88df9a97b63b3ff56d26975d3a57 Mon Sep 17 00:00:00 2001
From: Chen Liang <liach@openjdk.org>
Date: Wed, 27 Aug 2025 14:25:39 +0000
Subject: [PATCH] 8366028: MethodType::fromMethodDescriptorString should not
 throw UnsupportedOperationException for invalid descriptors

Reviewed-by: jvernee
---
 .../sun/invoke/util/BytecodeDescriptor.java   | 13 ++++++++---
 test/jdk/java/lang/invoke/MethodTypeTest.java | 23 ++++++++++++++++++-
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/src/java.base/share/classes/sun/invoke/util/BytecodeDescriptor.java b/src/java.base/share/classes/sun/invoke/util/BytecodeDescriptor.java
index 53fd6322758..76bbff2a610 100644
--- a/src/java.base/share/classes/sun/invoke/util/BytecodeDescriptor.java
+++ b/src/java.base/share/classes/sun/invoke/util/BytecodeDescriptor.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -96,8 +96,15 @@ public class BytecodeDescriptor {
             }
         } else if (c == '[') {
             Class<?> t = parseSig(str, i, end, loader);
-            if (t != null)
-                t = t.arrayType();
+            if (t != null) {
+                try {
+                    t = t.arrayType();
+                } catch (UnsupportedOperationException ex) {
+                    // Bad arrays, such as [V or more than 255 dims
+                    // We have a more informative IAE
+                    return null;
+                }
+            }
             return t;
         } else {
             return Wrapper.forBasicType(c).primitiveType();
diff --git a/test/jdk/java/lang/invoke/MethodTypeTest.java b/test/jdk/java/lang/invoke/MethodTypeTest.java
index c2ae4e0e84f..70949236066 100644
--- a/test/jdk/java/lang/invoke/MethodTypeTest.java
+++ b/test/jdk/java/lang/invoke/MethodTypeTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -22,6 +22,7 @@
  */
 
 /* @test
+ * @bug 8366028
  * @summary unit tests for java.lang.invoke.MethodType
  * @compile MethodTypeTest.java
  * @run testng/othervm test.java.lang.invoke.MethodTypeTest
@@ -35,6 +36,8 @@ import java.lang.reflect.Method;
 
 import java.util.*;
 import org.testng.*;
+
+import static org.testng.Assert.assertThrows;
 import static org.testng.AssertJUnit.*;
 import org.testng.annotations.*;
 
@@ -218,6 +221,24 @@ public class MethodTypeTest {
         return sb.toString().replace('.', '/');
     }
 
+    @DataProvider(name = "badMethodDescriptorStrings")
+    public String[] badMethodDescriptorStrings() {
+        return new String[] {
+                "(I)",
+                "(V)V",
+                "([V)V",
+                "(" + "[".repeat(256) + "J)I",
+                "(java/lang/Object)V",
+                "()java/lang/Object",
+        };
+    }
+
+    // JDK-8366028
+    @Test(dataProvider = "badMethodDescriptorStrings", expectedExceptions = IllegalArgumentException.class)
+    public void testFromMethodDescriptorStringNegatives(String desc) {
+        MethodType.fromMethodDescriptorString(desc, null);
+    }
+
     @Test
     public void testHasPrimitives() {
         System.out.println("hasPrimitives");