The solution is to simply press Ctrl-Alt-Del.
This happens on a laptop with the following setup (two physical hard drives, both encrypted):
So, there are two hard drives, first (sda) is encrypted with a password, the second (sdb) is encrypted with a file (in order not to be asked for a password).# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 238.5G 0 disk
├─sda1 8:1 0 487M 0 part /boot
├─sda2 8:2 0 1K 0 part
└─sda5 8:5 0 238G 0 part
└─sda5_crypt 254:0 0 238G 0 crypt
├─vg-swap 254:1 0 9.3G 0 lvm [SWAP]
└─vg-root 254:2 0 228.7G 0 lvm /
sdb 8:16 0 1.8T 0 disk
└─sdb1 8:17 0 1.8T 0 part
└─storage 254:3 0 1.8T 0 crypt /mnt/storage
sr0 11:0 1 1024M 0 rom
I have another laptop that has only one HDD for Linux and there are no problems.