char* dexOptGenerateCacheFileName(const char* fileName, const char* subFileName)
{
 char nameBuf[512];
 char absoluteFile[sizeof(nameBuf)];
 const size_t kBufLen = sizeof(nameBuf) - 1;
 const char* dataRoot;
 char* cp;

 /*
     * Get the absolute path of the Jar or DEX file.
     */
    absoluteFile[0] = '\0';
 if (fileName[0] != '/') {
 /*
         * Generate the absolute path.  This doesn't do everything it
         * should, e.g. if filename is "./out/whatever" it doesn't crunch
         * the leading "./" out, but it'll do.
         */
 if (getcwd(absoluteFile, kBufLen) == NULL) {

             ALOGE("Can't get CWD while opening jar file");
             return NULL;
         }
        strncat(absoluteFile, "/", kBufLen);
     }
    strncat(absoluteFile, fileName, kBufLen);
 
     /*
      * Append the name of the Jar file entry, if any.  This is not currently
     * required, but will be if we start putting more than one DEX file

      * in a Jar.
      */
     if (subFileName != NULL) {
        strncat(absoluteFile, "/", kBufLen);
        strncat(absoluteFile, subFileName, kBufLen);
     }
 
     /* Turn the path into a flat filename by replacing
     * any slashes after the first one with '@' characters.
     */
    cp = absoluteFile + 1;
 while (*cp != '\0') {
 if (*cp == '/') {
 *cp = '@';
 }
        cp++;
 }

 /* Build the name of the cache directory.
     */
    dataRoot = getenv("ANDROID_DATA");
 if (dataRoot == NULL)
        dataRoot = "/data";
    snprintf(nameBuf, kBufLen, "%s/%s", dataRoot, kCacheDirectoryName);
 if (strcmp(dataRoot, "/data") != 0) {
 int result = dexOptMkdir(nameBuf, 0700);
 if (result != 0 && errno != EEXIST) {
            ALOGE("Failed to create dalvik-cache directory %s: %s", nameBuf, strerror(errno));
 return NULL;
 }
 }
    snprintf(nameBuf, kBufLen, "%s/%s/%s", dataRoot, kCacheDirectoryName, kInstructionSet);
 if (strcmp(dataRoot, "/data") != 0) {
 int result = dexOptMkdir(nameBuf, 0700);
 if (result != 0 && errno != EEXIST) {
            ALOGE("Failed to create dalvik-cache directory %s: %s", nameBuf, strerror(errno));
 return NULL;
 }
 }

 
     /* Tack on the file name for the actual cache file path.
      */
    strncat(nameBuf, absoluteFile, kBufLen);
 
     ALOGV("Cache file for '%s' '%s' is '%s'", fileName, subFileName, nameBuf);
     return strdup(nameBuf);
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.