Android (ART) crash with error JNI DETECTED ERROR IN APPLICATION: jarray is an invalid stack indirect reference table or invalid reference

Android (ART) Crash: “JNI DETECTED ERROR IN APPLICATION: jarray is an invalid stack indirect reference table or invalid reference”

This error message signifies a serious problem within your Android application, often stemming from issues in Java Native Interface (JNI) code. This article will guide you through understanding the error, identifying common causes, and troubleshooting techniques.

Understanding the Error

The error “JNI DETECTED ERROR IN APPLICATION: jarray is an invalid stack indirect reference table or invalid reference” indicates a corruption in the memory space used by JNI to manage Java arrays.

What is JNI?

JNI is a bridge between Java and native code (C/C++). It allows you to call native functions from Java code and vice-versa. When this communication goes awry, errors like this arise.

Causes of the Error

• Incorrect JNI Call: Misusing JNI functions can lead to invalid array references, especially if you’re manipulating arrays outside the bounds of their allocated memory.
• Memory Corruption: Unmanaged memory leaks or buffer overflows in native code can corrupt the memory space associated with JNI arrays, leading to invalid references.
• JNI Version Mismatch: Incompatibility between the JNI version used in your native code and the version supported by the Android runtime.
• Native Library Issues: Issues within your native libraries, such as bugs or corrupted files, can also contribute to this error.
• Incorrect Array Handling: Misuse of array-related functions like `GetArrayElements()` or `ReleaseArrayElements()`.

Troubleshooting

1. Analyze the Stack Trace

Start by carefully examining the stack trace provided in the error message. It will pinpoint the location in your code where the error occurs.

2. Debug JNI Code

• Use a Debugger: Employ a debugger to step through your JNI code and inspect variables, memory locations, and function calls.
• Print Statements: Add logging statements in your native code to monitor the values of variables, array references, and function calls, especially within your JNI functions.

3. Check for Memory Issues

• Memory Leaks: Run your app with profiling tools to detect memory leaks in your native code.
• Buffer Overflows: Carefully examine your code for potential buffer overflows. Make sure array sizes are correctly handled and that data is written within valid bounds.

4. Verify JNI Compatibility

Ensure that your native code is compiled with the appropriate JNI version compatible with the target Android version you’re using.

5. Review Native Library Integrity

• Library Compatibility: Make sure that the native library you’re linking against is compatible with your Android architecture.
• Library Integrity: Check that the native library is not corrupted or missing files.

6. Examine JNI Array Handling

• GetArrayElements(): Ensure that you correctly use `GetArrayElements()` to obtain a pointer to the Java array and `ReleaseArrayElements()` to release the pointer after you’re done.
• Array Bounds: Verify that you’re accessing elements within the bounds of the Java array. Accessing outside of the bounds can lead to memory corruption.

Example: Incorrect JNI Call

The following code snippet demonstrates a potential error in using `GetArrayElements()`:

JNIEXPORT jint JNICALL
Java_com_example_myapp_NativeLib_sumArray(JNIEnv *env, jobject thiz, jintArray arr) {
  jint *elements = env->GetArrayElements(arr, NULL); // Get the array elements

  // ... some processing of elements

  // Release the pointer but forget to specify the mode!
  env->ReleaseArrayElements(arr, elements, NULL); // Should be JNI_ABORT or JNI_COMMIT

  return sum; // Sum calculated from the elements
}

In this example, the `ReleaseArrayElements()` function lacks the necessary mode argument (e.g., `JNI_ABORT` or `JNI_COMMIT`) to indicate how the changes to the array should be treated. This can lead to an invalid array state and, consequently, the “JNI DETECTED ERROR” message.

Conclusion

The “JNI DETECTED ERROR IN APPLICATION: jarray is an invalid stack indirect reference table or invalid reference” error signals an issue in your JNI code. By carefully examining the stack trace, debugging your JNI functions, checking for memory issues, and verifying JNI compatibility and array handling, you can identify the root cause and resolve this error.