Created attachment 141538 [details]
crash dump as suggested by the error log
Experiencing this on a X1 Carbon 2017, kernels 4.15 and 4.18 on ubuntu 18.04. System starts properly only with nomodeset, otherwise the screen freezes right around login. Eventually I manage to switch to another tty and pull the logs.
Sep 12 16:06:42 carbon kernel: [drm] GPU HANG: ecode 9:0:0x85df3eff, in gnome-shell , reason: hang on rcs0, action: reset
*** This bug has been marked as a duplicate of bug 109250 ***