I'm experiencing the same thing on Ubuntu Xenial. I initially thought it was only on using Alt+left/right, but did a Alt+F4 to close a window just now, and the window did close but it switched to VT4 as well. I think it started happening today on my system.
Linux 4.4.0-116-generic #140-Ubuntu SMP Mon Feb 12 21:23:04 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1710637 Title: Input falls through to gdm3 and terminates the session on Ctrl+C after udevadm trigger is executed under wayland Status in Snappy: Won't Fix Status in console-setup package in Ubuntu: Fix Released Status in gdm3 package in Ubuntu: Invalid Status in gnome-shell package in Ubuntu: Invalid Status in mutter package in Ubuntu: Invalid Status in systemd package in Ubuntu: Invalid Status in console-setup source package in Trusty: New Status in gdm3 source package in Trusty: New Status in gnome-shell source package in Trusty: New Status in mutter source package in Trusty: New Status in systemd source package in Trusty: New Status in console-setup source package in Xenial: New Status in gdm3 source package in Xenial: New Status in gnome-shell source package in Xenial: New Status in mutter source package in Xenial: New Status in systemd source package in Xenial: New Bug description: = Test Cases = Test Case 1: - Login under Wayland (session Ubuntu) - Open a terminal - snap install gimp - Wait until installation finishes successfully - In the terminal window press CTRL+C Result: - Expected: ^C is displayed in the terminal and the prompt is at the start of a new line - Actual: The session is terminated and the login screen is displayed Test Case 2: - Login under Wayland (session Ubuntu) - Open a terminal and type the following command: $ sudo udevadm trigger - In the terminal window press CTRL+C Result - Expected: ^C is displayed in the terminal and the prompt is at the start of a new line - Actual: The session is terminated and the login screen is displayed = Original Description = Multiple times a day I find myself without a session after hitting Ctrl+C in a terminal, it seems the input falls through the Ubuntu/GNOME session and to gdm, which itself decides to terminate. Even worse, when this happens, you can briefly see your login password in plaintext in the virtual terminal. You can see the password however long you want if you stop the gdm service when this happens. I don't have a good way to reproduce, but it seems locking the session with a keyboard shortcut, subsequently unlocking it, maybe suspending, at some point brings this behaviour into the picture, until the session dies with a Ctrl+C. ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: gdm3 3.24.2-1ubuntu9 ProcVersionSignature: Ubuntu 4.11.0-13.19-generic 4.11.12 Uname: Linux 4.11.0-13-generic x86_64 NonfreeKernelModules: zfs zunicode zavl zcommon znvpair ApportVersion: 2.20.6-0ubuntu5 Architecture: amd64 CurrentDesktop: GNOME Date: Mon Aug 14 15:54:34 2017 InstallationDate: Installed on 2016-05-06 (464 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) SourcePackage: gdm3 UpgradeStatus: Upgraded to artful on 2017-07-19 (25 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/snappy/+bug/1710637/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : firstname.lastname@example.org Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp