Saturday, 5. May 2007
Topic: COMPUTER - on May 5, 2007 at 12:09:00 PM CEST
How my lack of understanding of how processes exit on Windows XP forced a security patch to be recalled
Last year, a Windows security update got a lot of flack for causing some machines to hang, and it was my fault. (This makes messing up a demo at the Financial Analysts Meeting look like small potatoes.)
The security fix addressed a category of attacks wherein people could construct shortcut files or other items which specified a CLSID that was never intended to be used as a shell extension. As we saw earlier, lots of people mess up IUnknown::QueryInterface, and if you pass the CLSID of one of these buggy implementations, Explorer would dutifully create it and try to use it, and then bad things would happen. The object might crash or hang or even corrupt memory and keep running (sort of).
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