From 0dd0abed2ab706a47824bbc96ae3dd96f6a65b9e Mon Sep 17 00:00:00 2001
From: Douglas Q Hawkins <douglas.hawkins@datadoghq.com>
Date: Tue, 1 Sep 2026 17:40:30 -0400
Subject: [PATCH] Fix NPE in DatabaseClientDecorator when JDBC connection has
 no db type

processDatabaseType/dbService dereferenced the NamingEntry returned by
CACHE.computeIfAbsent(dbType, NamingEntry::new) without checking for
null. FixedSizeCache.computeIfAbsent returns null for a null key
without invoking the producer, so a null dbType() (e.g. an
undetermined DBInfo.getType()) led to a NullPointerException in
tracing instrumentation instead of a graceful no-op.

Guard on dbType == null directly instead of inferring it from the
cache's return value, and add a test exercising both methods with a
null dbType.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
---
 .../decorator/DatabaseClientDecorator.java    | 12 +++-
 ...DatabaseClientDecoratorNullDbTypeTest.java | 70 +++++++++++++++++++
 2 files changed, 79 insertions(+), 3 deletions(-)
 create mode 100644 dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorNullDbTypeTest.java

diff --git a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecorator.java b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecorator.java
index fa105776113..79d08f4139a 100644
--- a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecorator.java
+++ b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecorator.java
@@ -96,8 +96,10 @@ public String dbService(final String dbType, final String instanceName) {
     if (instanceName != null && Config.get().isDbClientSplitByInstance()) {
       return dbClientService(instanceName);
     }
-    final NamingEntry entry = CACHE.computeIfAbsent(dbType, NamingEntry::new);
-    return entry.getService();
+    if (dbType == null) {
+      return null;
+    }
+    return CACHE.computeIfAbsent(dbType, NamingEntry::new).getService();
   }
 
   public String dbClientService(final String instanceName) {
@@ -144,11 +146,15 @@ public void onRawStatement(AgentSpan span, String sql) {
   }
 
   protected void processDatabaseType(AgentSpan span, String dbType) {
+    if (dbType == null) {
+      return;
+    }
+
     final NamingEntry namingEntry = CACHE.computeIfAbsent(dbType, NamingEntry::new);
     span.setTag(DB_TYPE, namingEntry.dbType);
     postProcessServiceAndOperationName(span, namingEntry);
 
-    if (Config.get().isAppSecRaspEnabled() && dbType != null) {
+    if (Config.get().isAppSecRaspEnabled()) {
       BiConsumer<RequestContext, String> connectDbCallback =
           AgentTracer.get()
               .getCallbackProvider(RequestContextSlot.APPSEC)
diff --git a/dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorNullDbTypeTest.java b/dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorNullDbTypeTest.java
new file mode 100644
index 00000000000..681ceb460a2
--- /dev/null
+++ b/dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorNullDbTypeTest.java
@@ -0,0 +1,70 @@
+package datadog.trace.bootstrap.instrumentation.decorator;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import datadog.trace.bootstrap.instrumentation.api.AgentSpan;
+import org.junit.jupiter.api.Test;
+
+class DatabaseClientDecoratorNullDbTypeTest {
+
+  private final AgentSpan span = mock(AgentSpan.class);
+  private final DatabaseClientDecorator<Object> decorator =
+      new DatabaseClientDecorator<Object>() {
+        @Override
+        protected String[] instrumentationNames() {
+          return new String[] {"test"};
+        }
+
+        @Override
+        protected CharSequence spanType() {
+          return "test-type";
+        }
+
+        @Override
+        protected CharSequence component() {
+          return "test-component";
+        }
+
+        @Override
+        protected String service() {
+          return "test-service";
+        }
+
+        @Override
+        protected String dbType() {
+          return null;
+        }
+
+        @Override
+        protected String dbUser(Object connection) {
+          return null;
+        }
+
+        @Override
+        protected String dbInstance(Object connection) {
+          return null;
+        }
+
+        @Override
+        protected CharSequence dbHostname(Object connection) {
+          return null;
+        }
+      };
+
+  @Test
+  void processDatabaseTypeWithNullDbTypeDoesNotThrowOrTag() {
+    assertDoesNotThrow(() -> decorator.processDatabaseType(span, null));
+
+    verify(span, never()).setTag(anyString(), anyString());
+  }
+
+  @Test
+  void dbServiceWithNullDbTypeReturnsNull() {
+    assertNull(decorator.dbService(null, null));
+  }
+}