Confirming this bug on two different laptops (Dell and Lenovo) ; both running Debian 9 with kernel 4.9.0-6.
Booting from the previous kernel (4.9.0-6) works as expected (i.e. gdm starts in under five minutes!). -- Securely sent with Tutanota. Claim your encrypted mailbox today! https://tutanota.com <https://tutanota.com>