In all honesty, this is one of the most interesting bugs I know. Within all the people that have it, there are variations to which causes it in the first place. What works for me (Debian Jessie with Mesa/libc6 from Backports, for example) might still cause the crash for some people. What I do know is that it's not caused by faulty hardware. It could be for some, but seriously doubt it it's the cause for 99.99% of people experiencing the issue.