Don't allow TGA reader to read images larger than 4GB even in 64-bit (#440)

DirectXTex/DirectXTex.h

@@ -115,6 +115,9 @@ namespace DirectX
 
         CP_FLAGS_8BPP = 0x40000,
         // Override with a legacy 8 bits-per-pixel format size
+
+        CP_FLAGS_LIMIT_4GB = 0x10000000,
+        // Don't allow pixel allocations in excess of 4GB (always true for 32-bit)
     };
 
     HRESULT __cdecl ComputePitch(

DirectXTex/DirectXTexHDR.cpp

@@ -715,7 +715,7 @@ HRESULT DirectX::LoadFromHDRMemory(const void* pSource, size_t size, TexMetadata
     if (remaining == 0)
         return E_FAIL;
 
-    hr = image.Initialize2D(mdata.format, mdata.width, mdata.height, 1, 1);
+    hr = image.Initialize2D(mdata.format, mdata.width, mdata.height, 1, 1, CP_FLAGS_LIMIT_4GB);
     if (FAILED(hr))
         return hr;
 

DirectXTex/DirectXTexImage.cpp

@@ -123,6 +123,12 @@ HRESULT DirectX::Internal::DetermineImageArray(
     }
 #else
     static_assert(sizeof(size_t) == 8, "Not a 64-bit platform!");
+
+    if ((cpFlags & CP_FLAGS_LIMIT_4GB) && (totalPixelSize > UINT32_MAX))
+    {
+        nImages = pixelSize = 0;
+        return HRESULT_E_ARITHMETIC_OVERFLOW;
+    }
 #endif
 
     nImages = nimages;

DirectXTex/DirectXTexTGA.cpp

@@ -1683,7 +1683,7 @@ HRESULT DirectX::LoadFromTGAMemory(
 
     const void* pPixels = static_cast<const uint8_t*>(pSource) + offset + paletteOffset;
 
-    hr = image.Initialize2D(mdata.format, mdata.width, mdata.height, 1, 1);
+    hr = image.Initialize2D(mdata.format, mdata.width, mdata.height, 1, 1, CP_FLAGS_LIMIT_4GB);
     if (FAILED(hr))
         return hr;
 
@@ -1856,7 +1856,7 @@ HRESULT DirectX::LoadFromTGAFile(
     #endif
     }
 
-    hr = image.Initialize2D(mdata.format, mdata.width, mdata.height, 1, 1);
+    hr = image.Initialize2D(mdata.format, mdata.width, mdata.height, 1, 1, CP_FLAGS_LIMIT_4GB);
     if (FAILED(hr))
         return hr;