PSA for any fellow Linux CS players out there: the June 20 update to CSGO made the game crash on every launch for me until I disabled the Steam overlay. Not sure exactly what the cause was, but I suspect something with CSGO doesn’t play nice with the redesigned Steam overlay.
I had a similar bug where the game would crash any time I opened the overlay, and like you suggested, disabling the overlay works as a temporary patch. It means that I can’t buy items in game, though.