(In reply to comment #8)
> So since you find root case, LightDM log is not necessary now, I am correct?

No, I didn't find the root cause. I am only assuming (based on the last message
in your Xorg.0.log file) that you are seeing the same kind of a crash that I
have been seeing recently.

So I would like you to test if the patch that I posted fixes the problem for
you. If it does, then there are two open issues that remain: a) should we push
my patch upstream (i.e. to at least prevent the crash of affected users like
you) and b) what really causes the double-free. The latter is what we have no
idea about yet.

Any additional logs that you can produce in the meantime would be useful.