Microsoft Edge Chakra chakra!Js::GlobalObject Integer Overflow

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Report by Huang Anwen, He Xiaoxiao of ichunqiu Ker Team

There is a classic heap overflow when eval a string which large enough in Chakra!
This issue can be reproduced steadly in uptodate Edge in Win10 WIP.
An exception will occur immediatly when opening POC.html in Edge.



    //ChakraCore-master\lib\Runtime\Library\GlobalObject.cpp

    ScriptFunction* GlobalObject::DefaultEvalHelper(ScriptContext* scriptContext, const char16 *source, int sourceLength, ModuleID moduleID, uint32 grfscr, LPCOLESTR pszTitle, BOOL registerDocument, BOOL isIndirect, BOOL strictMode)
    {
        Assert(sourceLength >= 0);
        AnalysisAssert(scriptContext);
        if (scriptContext->GetThreadContext()->EvalDisabled())
        {
            throw Js::EvalDisabledException();
        }

#ifdef PROFILE_EXEC
        scriptContext->ProfileBegin(Js::EvalCompilePhase);