diff --git a/core/jni/android_content_res_ApkAssets.cpp b/core/jni/android_content_res_ApkAssets.cpp
index fc12e174b55d2..a8d72316036ea 100644
--- a/core/jni/android_content_res_ApkAssets.cpp
+++ b/core/jni/android_content_res_ApkAssets.cpp
@@ -459,8 +459,12 @@ static jobject NativeGetOverlayableInfo(JNIEnv* env, jclass /*clazz*/, jlong ptr
     return nullptr;
   }
 
-  auto overlayable_name_native = std::string(env->GetStringUTFChars(overlayable_name, NULL));
+  const char* overlayable_name_native = env->GetStringUTFChars(overlayable_name, nullptr);
+  if (overlayable_name_native == nullptr) {
+      return nullptr;
+  }
   auto actor = overlayable_map.find(overlayable_name_native);
+  env->ReleaseStringUTFChars(overlayable_name, overlayable_name_native);
   if (actor == overlayable_map.end()) {
     return nullptr;
   }
diff --git a/core/jni/android_hardware_camera2_DngCreator.cpp b/core/jni/android_hardware_camera2_DngCreator.cpp
index db33863ddd772..c947fba2dbd92 100644
--- a/core/jni/android_hardware_camera2_DngCreator.cpp
+++ b/core/jni/android_hardware_camera2_DngCreator.cpp
@@ -48,6 +48,7 @@
 
 #include <jni.h>
 #include <nativehelper/JNIHelp.h>
+#include <nativehelper/ScopedUtfChars.h>
 
 using namespace android;
 using namespace img_utils;
@@ -1264,16 +1265,14 @@ static void DngCreator_init(JNIEnv* env, jobject thiz, jobject characteristicsPt
 
     sp<NativeContext> nativeContext = new NativeContext(characteristics, results);
 
-    const char* captureTime = env->GetStringUTFChars(formattedCaptureTime, nullptr);
-
-    size_t len = strlen(captureTime) + 1;
-    if (len != NativeContext::DATETIME_COUNT) {
+    ScopedUtfChars captureTime(env, formattedCaptureTime);
+    if (captureTime.size() + 1 != NativeContext::DATETIME_COUNT) {
         jniThrowException(env, "java/lang/IllegalArgumentException",
                 "Formatted capture time string length is not required 20 characters");
         return;
     }
 
-    nativeContext->setCaptureTime(String8(captureTime));
+    nativeContext->setCaptureTime(String8(captureTime.c_str()));
 
     DngCreator_setNativeContext(env, thiz, nativeContext);
 }