Memory corruption using clEnqueueWriteBuffer

#include <iostream>
#include <vector>

#ifdef __APPLE__
#include <OpenCL/opencl.h>
#else
#include <CL/cl.h>
#endif

#define MAX_SOURCE_SIZE (512)

int main()
{
    std::vector<cl_device_id> deviceVector;
    cl_context context = NULL;
    cl_command_queue command_queue = NULL;
    cl_program program = NULL;
    cl_kernel kernel = NULL;
    cl_platform_id platforms[8];
    cl_uint ret_num_devices;
    cl_uint ret_num_platforms;
    cl_int ret;
    cl_mem memArray = NULL;
    float *Array;

    //--------------------------KERNEL---------------------------------
    char *source_str;
    source_str = (char*)malloc(MAX_SOURCE_SIZE);

    source_str =    "#if defined cl_intel_printf \n" \
                    "   #pragma OPENCL EXTENSION cl_intel_printf :enable \n" \
                    "#else \n" \
                    "   #pragma OPENCL EXTENSION cl_amd_printf :enable \n" \
                    "#endif \n" \
                    " \n" \
                    "__kernel void KernelTest(__global const float * Array) \n" \
                    "   { \n" \
                    "   const int i = get_global_id(0); \n" \
                    "   const int j = get_global_id(1); \n" \
                    "   const int k = get_global_id(2); \n" \
                    " \n" \
                    "   if(i==0 && j==0 && k==0) \n" \
                    "       printf(\"\\r\\nArray GPU: %f \", Array[0]); \n" \
                    "   } \n" \
                    "\n";

    size_t source_size = strlen(source_str);
    //------------------------------------------------------------------


    std::cout << "\r\nInitializing" << std::endl;
    //--------------------------INITIALIZE---------------------------------
    ret = clGetPlatformIDs(8, platforms, &ret_num_platforms);
    std::cout << " clGetPlatformIDs " << ret << std::endl;
    std::cout << " Number of Platforms:  " << ret_num_platforms << std::endl;

    for (int i=0; i<ret_num_platforms; i++)
    {
        cl_device_id devices[8];
        ret = clGetDeviceIDs(platforms[i], CL_DEVICE_TYPE_ALL, 8, devices, &ret_num_devices);
        std::cout << " clGetDeviceIDs " << ret << std::endl << std::endl;

        for(int j=0; j<ret_num_devices; j++){
            if(std::find(deviceVector.begin(), deviceVector.end(), devices[j]) == deviceVector.end())
                deviceVector.push_back(devices[j]);
        }
    }

    for (int i=0; i<deviceVector.size(); i++)
    {
        char buffer[1024];
        cl_uint buf_uint;
        cl_ulong buf_ulong;
        clGetDeviceInfo(deviceVector[i], CL_DEVICE_NAME, sizeof(buffer), buffer, NULL);
        std::cout << " -- "<< i << " -- DEVICE_NAME: " << buffer << std::endl;
    }

    int option = 0;
    do{
        std::cout << "\r\nOption: ";
        std::cin >> option;
    }while(option<0 || option>deviceVector.size()-1);

    context = clCreateContext(NULL, 1, &deviceVector[option], NULL, NULL, &ret);
    std::cout << " clCreateContext " << ret << std::endl;

    command_queue = clCreateCommandQueue(context, deviceVector[option], 0, &ret);
    std::cout << " clCreateCommandQueue " << ret << std::endl;

    program = clCreateProgramWithSource(context, 1, (const char **)&source_str, (const size_t *)&source_size, &ret);
    std::cout << " clCreateProgramWithSource " << ret << std::endl;

    ret = clBuildProgram(program, 1, &deviceVector[option], NULL, NULL, NULL);
    std::cout << " clBuildProgram " << ret << std::endl;

    if(ret){
        size_t log_size;
        clGetProgramBuildInfo(program, deviceVector[option], CL_PROGRAM_BUILD_LOG, 0, NULL, &log_size);
        char *log = (char *) malloc(log_size);
        clGetProgramBuildInfo(program, deviceVector[option], CL_PROGRAM_BUILD_LOG, log_size, log, NULL);
        std::cout << log << std::endl;

        getchar();getchar();
        return ret;
    }

    kernel = clCreateKernel(program, "KernelTest", &ret);
    std::cout << " clCreateKernel " << ret << std::endl;
    //------------------------------------------------------------------


    std::cout << "\r\nKerneling" << std::endl;
    //--------------------------EXECUTE---------------------------------
    size_t mGlobalWorkSizePtr[] = { 100, 100, 62 };
    size_t mLocalWorkSizePtr[] = { 5, 5, 1 };

    int SizeArray = 0;
    for(int j=1;j<100;j++){

        //Array memory allocation, starting with 4MB in first iteration to 400MB in last one
        SizeArray = j * 1000000 * sizeof(float);
        Array = (float*)malloc(SizeArray);
        memset(Array, 0, SizeArray);

        //Give the array's first element some nonzero value
        //This is the value that is expected to be printed by the kernel execution
        Array[0] = j;
        std::cout << "\r\n\r\n Size: " << SizeArray/sizeof(float) << std::endl << std::endl;

        //Create the buffer where the content of the array will be stored
        memArray = clCreateBuffer(context, CL_MEM_READ_WRITE, SizeArray, NULL, &ret);
        std::cout << " clCreateBuffer Array " << ret << std::endl;

        //Write the array contents into the buffer inside the device
        ret = clEnqueueWriteBuffer(command_queue, memArray, CL_TRUE, 0, SizeArray, Array, 0, NULL, NULL);
        std::cout << " clEnqueueWriteBuffer Array " << ret << std::endl;
        ret = clSetKernelArg(kernel, 0, sizeof(cl_mem), (void *)&memArray);
        std::cout << " clSetKernelArg memArray " << ret << std::endl;

        std::cout << "\r\nArray CPU : " << Array[0] << std::endl;
        getchar();

        //Execute the kernel where the content of the first element of the array will be printed
        ret = clEnqueueNDRangeKernel(command_queue, kernel, 3, NULL, mGlobalWorkSizePtr, mLocalWorkSizePtr, 0, NULL,NULL);
        ret = clFinish(command_queue);

/****** FAIL! Kernel prints correct value of Array's first element ONLY IN SOME ITERATIONS (when it fails zero values are printed)! Depending on SizeArray :?? ******/

        free(Array);
        ret = clReleaseMemObject(memArray);
    }

    ret = clFlush(command_queue);
    ret = clFinish(command_queue);
    ret = clReleaseKernel(kernel);
    ret = clReleaseProgram(program);
    ret = clReleaseCommandQueue(command_queue);
    ret = clReleaseContext(context);

    free(source_str);
    //------------------------------------------------------------------

    return 0;
}