My child was able to crash gdm

[Jussi Lind]

I let my 1-year-old child play with the login screen for ~5 minutes. After hitting all kinds of keys (the sequence seemed to be very complicated) we ended up with a black screen with mouse cursor only slowly responding to mouse movement and lagging behind.

I couldn't do anything else but reset the PC.

First this seems to be funny, but then you realize how embarrassing it is. It absolutely should not be possible to crash the login screen just like that. How is that even possible? The login screen should just either accept a password or reject it no matter what keys are being pressed.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gdm3 3.28.3-0ubuntu18.04.4
ProcVersionSignature: Ubuntu 5.3.0-45.37~18.04.1-generic 5.3.18
Uname: Linux 5.3.0-45-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.14
Architecture: amd64
Date: Sat Apr 4 19:24:38 2020
InstallationDate: Installed on 2019-11-09 (146 days ago)
InstallationMedia: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
SourcePackage: gdm3
UpgradeStatus: No upgrade log present (probably fresh install)

[Sebastien Bacher (seb128)]

Thank you for your bug report, could you include your journalctl log from that session?

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It sounds like some part of the system has crashed. To help us find the cause of the crash please follow these steps:

1. Look in /var/crash for crash files and if found run:
    ubuntu-bug YOURFILE.crash
Then tell us the ID of the newly-created bug.

2. If step 1 failed then look at https://errors.ubuntu.com/user/ID where ID is the content of file /var/lib/whoopsie/whoopsie-id on the machine. Do you find any links to recent problems on that page? If so then please send the links to us.

3. If step 2 also failed then apply the workaround from bug 994921, reboot, reproduce the crash, and retry step 1.

Please take care to avoid attaching .crash files to bugs as we are unable to process them as file attachments. It would also be a security risk for yourself.

[Launchpad Janitor (janitor)]

[Expired for gdm3 (Ubuntu) because there has been no activity for 60 days.]