Heap corruption from this method - c++

Question

I'm getting a heap corruption error whenever the following method is called:
bool TextureData::loadFromMemory(char* memData, int w, int h)
{
GLuint texId;
glEnable(GL_TEXTURE_2D);
glGenTextures(1, &texId);
glTextureId = static_cast<int>(texId);
glBindTexture(GL_TEXTURE_2D, texId); // Bind the texture
glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
memWidth = width = w;
memHeight = height = h;
int newPad = 0;//(4 - (w*4)%4)==4 ? 0 : (4 - (w*4)%4);
int oldPad = 0;//(4 - (w*3)%4)==4 ? 0 : (4 - (w*3)%4);
size_t size = (width+newPad)*height * 4;
char* data = 0;
data = new char[size];
memcpy(data, memData, size * sizeof(char));
// Texture generation
gluBuild2DMipmaps(GL_TEXTURE_2D, 4, memWidth, memHeight, GL_RGBA, GL_UNSIGNED_BYTE, data);
delete [] data;
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
return true;
}
Where the char* data array given to this method is generated like this:
int imageSize = width_ * height_ * 4;
data_ = new char[imageSize];
SDL_LockSurface(TextureImage);
for (Uint y = 0; y < height_; ++y)
{
for (Uint x = 0; x < width_; ++x)
{
size_t currPixel = (y * width_ + x) * 4;
SDL_Color rgb;
Uint32 data = getPixel(TextureImage, x, y);
SDL_GetRGB(data, TextureImage->format, &rgb.r, &rgb.g, &rgb.b);
data_[currPixel] = (char)rgb.r;
data_[currPixel + 1] = (char)rgb.g;
data_[currPixel + 2] = (char)rgb.b;
data_[currPixel + 3] = (char)255;
}
}
SDL_UnlockSurface(TextureImage);
SDL_FreeSurface(TextureImage);
I can't figure out why the loadFromMemory method is causing a heap corruption and need a review, if anyone has any ideas.