diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
index a924f10fb366..5e59eb33b4bd 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
@@ -419,11 +419,13 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
     }
   }
 
+  private def simpleClassName: String = Utils.getSimpleName(this.getClass)
+
   /**
    * Returns the name of this type of TreeNode.  Defaults to the class name.
    * Note that we remove the "Exec" suffix for physical operators here.
    */
-  def nodeName: String = getClass.getSimpleName.replaceAll("Exec$", "")
+  def nodeName: String = simpleClassName.replaceAll("Exec$", "")
 
   /**
    * The arguments that should be included in the arg string.  Defaults to the `productIterator`.
@@ -610,7 +612,7 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product {
   protected def jsonFields: List[JField] = {
     val fieldNames = getConstructorParameterNames(getClass)
     val fieldValues = productIterator.toSeq ++ otherCopyArgs
-    assert(fieldNames.length == fieldValues.length, s"${getClass.getSimpleName} fields: " +
+    assert(fieldNames.length == fieldValues.length, s"$simpleClassName fields: " +
       fieldNames.mkString(", ") + s", values: " + fieldValues.map(_.toString).mkString(", "))
 
     fieldNames.zip(fieldValues).map {
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/trees/TreeNodeSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/trees/TreeNodeSuite.scala
index e37cf8a8e217..883f673cc4e4 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/trees/TreeNodeSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/trees/TreeNodeSuite.scala
@@ -32,7 +32,7 @@ import org.apache.spark.sql.catalyst.{AliasIdentifier, FunctionIdentifier, Inter
 import org.apache.spark.sql.catalyst.catalog._
 import org.apache.spark.sql.catalyst.dsl.expressions.DslString
 import org.apache.spark.sql.catalyst.expressions._
-import org.apache.spark.sql.catalyst.expressions.codegen.CodegenFallback
+import org.apache.spark.sql.catalyst.expressions.codegen.{CodegenContext, CodegenFallback, ExprCode}
 import org.apache.spark.sql.catalyst.plans.{LeftOuter, NaturalJoin}
 import org.apache.spark.sql.catalyst.plans.logical.{LeafNode, SubqueryAlias, Union}
 import org.apache.spark.sql.catalyst.plans.physical.{IdentityBroadcastMode, RoundRobinPartitioning, SinglePartition}
@@ -617,4 +617,39 @@ class TreeNodeSuite extends SparkFunSuite {
     val expected = Coalesce(Stream(Literal(1), Literal(3)))
     assert(result === expected)
   }
+
+  object MalformedClassObject extends Serializable {
+    // Backport notes: this class inline-expands TaggingExpression from Spark 3.1
+    case class MalformedNameExpression(child: Expression) extends UnaryExpression {
+      override def nullable: Boolean = child.nullable
+      override def dataType: DataType = child.dataType
+
+      override protected def doGenCode(ctx: CodegenContext, ev: ExprCode): ExprCode =
+        child.genCode(ctx)
+
+      override def eval(input: InternalRow): Any = child.eval(input)
+    }
+  }
+
+  test("SPARK-32999: TreeNode.nodeName should not throw malformed class name error") {
+    val testTriggersExpectedError = try {
+      classOf[MalformedClassObject.MalformedNameExpression].getSimpleName
+      false
+    } catch {
+      case ex: java.lang.InternalError if ex.getMessage.contains("Malformed class name") =>
+        true
+      case ex: Throwable => throw ex
+    }
+    // This test case only applies on older JDK versions (e.g. JDK8u), and doesn't trigger the
+    // issue on newer JDK versions (e.g. JDK11u).
+    assume(testTriggersExpectedError, "the test case didn't trigger malformed class name error")
+
+    val expr = MalformedClassObject.MalformedNameExpression(Literal(1))
+    try {
+      expr.nodeName
+    } catch {
+      case ex: java.lang.InternalError if ex.getMessage.contains("Malformed class name") =>
+        fail("TreeNode.nodeName should not throw malformed class name error")
+    }
+  }
 }