Bug Hunting Open-Source vs. Proprietary Software
PreacherTom writes "An analysis comparing the top 50 open-source software projects to proprietary software from over 100 different companies was conducted by Coverity, working in conjunction with the Department of Homeland Security and Stanford University. The study found that no open source project had fewer software defects than proprietary code. In fact, the analysis demonstrated that proprietary code is, on average, more than five times less buggy. On the other hand, the open-source software was found to be of greater average overall quality. Not surprisingly, dissenting opinions already exist, claiming Coverity's scope was inappropriate to their conclusions."
...and while it is on the list on the web page, I was happy to determine that most of the issues they found were false alarms. They found three real bugs, none of which were likely to bite, and even if they did bite it is not exploitable. Nonetheless, those bugs probably wouldn't have been found otherwise, so I was happy for the scan.
Rather than brag (I won't say who I am or the name of my project), I'm just going to sit back and read all the defensive flames from self-appointed "security experts" whose open-source project didn't do so well. After all the flames from these "security experts" that I've endured, I'm going to enjoy watching them squirm.
It's karma.
The article makes it quite clear that the proprietary software which is much better that open source is mission-critical software. A class of software where ensuring minimum bugs is a top priority, and also a class of software which mostly does just not exist in OSS. If you are an OSS developer, would you try to develop open source air traffic control software? And even if yes, how would you do it anyway?
Basically, my own conclusion from reading the article was that it IS possible to write excellent software with very few bugs, if that is a top priority. And, that the author seems to say that while mission-critical software (which happens to be proprietary) is fortunately much better than the rest, among all that other non-mission-critical software, open source tends to be better than proprietary.
Not surprising, and quite encouraging...
The selection of programs from the two populations of programs (open source, proprietary) are not going to be comparable: vendors of proprietary software have a say over which code gets scanned, and they are going to select a different population of programs than the company selected for open source projects. This isn't a fixable problem: there is no way of doing this sort of study so that you can compare the two data sets. The best they could do is compare something like OpenOffice against Microsoft Office, or Apache against IIS.
Furthermore, Coverity simply cannot accomplish what they claim to accomplish: there is no way of detecting "bugs" automatically--if there were, compilers would already be doing it. Coverity effectively does little more than compare code against a set of internal coding conventions; that can be useful if it's done right, but it's not a measure of code quality. Some completely correct code will score thousands of violations against their tool, while other code may contain thousands of bugs, none of which register. Furthermore, it is likely that a lot of their customers are Windows based and that Coverity is biased towards Windows-based coding conventions, giving more false positives on non-Windows code. Before publishing such comparisons, Coverity first would need to demonstrate that their tool does not contain such biases.
Finally, and perhaps most importantly, the company isn't publishing its data, so nobody can verify or even evaluate their claims. Not only do they fail to publish their raw data (obviously, they can't do that for proprietary software), they also fail to list their summary statistics by vendor and project (which they could, but obviously won't do). They don't even give a summary statistic by class of application, class of organization, and code size. Their results are meaningless because they're not reproducible.
These numbers tell you nothing about FOSS code quality relative to commercial code quality. What they tell you is that Coverity apparently doesn't know how to do statistics, misrepresents what their product can do, and doesn't know how to report experimental results properly. Now, do you want to put your trust in such a company?
SIGSEGV caught, terminating
wait... not that kind of sig.