Buffer Overrun with GPUSkinCache

In GPUSkinCache, based on the conditional expression:

if (CacheCurrentFloatOffset + NumRWFloats > (uint32)GGPUSkinCacheBufferSize)
	{
		// Can't fit this
		INC_DWORD_STAT(STAT_GPUSkinCache_SkippedForMemory);
		return -1;
	}

the licensee is stating that it is possible for skinning to execute even though there is no space the result.

They suggest replacing the code with:

 if ((CacheCurrentFloatOffset + NumRWFloats) * sizeof(float) > SkinCacheBuffer[UAVIndex].NumBytes)

1. Open UE4.sln
2. Navigate to GPUSkinCache.cpp line 485
3. Notice the conditional expression:

   if (CacheCurrentFloatOffset + NumRWFloats > (uint32)GGPUSkinCacheBufferSize)
   	{
   		// Can't fit this
   		INC_DWORD_STAT(STAT_GPUSkinCache_SkippedForMemory);
   		return -1;
   	}

4. The licensee suggests replacing the expression with:

    if ((CacheCurrentFloatOffset + NumRWFloats) * sizeof(float) > SkinCacheBuffer[UAVIndex].NumBytes)

Result: The licensee suggests this code would prevent the buffer overrun.