This is a valid question. Syzkaller is definitely one such tool that is open source, but the tool we've been using for the longest is internal only.
The reason it's not open source is because it's built on a lot of internal tools and it would be hard to separate out those dependencies. For example it relies on our custom VMM. We've discussed refactoring it so that we could get rid of the dependencies and open sourcing it, but that work has to be balanced with other priorities.
The reason it's not open source is because it's built on a lot of internal tools and it would be hard to separate out those dependencies. For example it relies on our custom VMM. We've discussed refactoring it so that we could get rid of the dependencies and open sourcing it, but that work has to be balanced with other priorities.