diff -up qt-x11-opensource-src-4.5.3/src/3rdparty/webkit/WebCore/css/CSSParser.cpp.cve-2010-0046-css-format-mem-corruption qt-x11-opensource-src-4.5.3/src/3rdparty/webkit/WebCore/css/CSSParser.cpp
--- qt-x11-opensource-src-4.5.3/src/3rdparty/webkit/WebCore/css/CSSParser.cpp.cve-2010-0046-css-format-mem-corruption	2009-09-29 13:01:35.000000000 +0200
+++ qt-x11-opensource-src-4.5.3/src/3rdparty/webkit/WebCore/css/CSSParser.cpp	2010-02-04 15:00:24.778776273 +0100
@@ -3085,6 +3085,12 @@ bool CSSParser::parseFontWeight(bool imp
     return false;
 }
 
+static bool isValidFormatFunction(CSSParserValue* val)
+{
+    CSSParserValueList* args = val->function->args;
+    return equalIgnoringCase(val->function->name, "format(") && (args->current()->unit == CSSPrimitiveValue::CSS_STRING || args->current()->unit == CSSPrimitiveValue::CSS_IDENT);
+}
+
 bool CSSParser::parseFontFaceSrc()
 {
     RefPtr<CSSValueList> values(CSSValueList::createCommaSeparated());
@@ -3111,7 +3117,7 @@ bool CSSParser::parseFontFaceSrc()
                     CSSParserValue* a = args->current();
                     uriValue.clear();
                     parsedValue = CSSFontFaceSrcValue::createLocal(a->string);
-                } else if (equalIgnoringCase(val->function->name, "format(") && allowFormat && uriValue) {
+                } else if (allowFormat && uriValue && isValidFormatFunction(val)) {
                     expectComma = true;
                     allowFormat = false;
                     uriValue->setFormat(args->current()->string);