gdm segfault when changing session between users

[Hassan El Jacifi]

Can't switch user session without crashing the hole system. Forced to reboot as gdm crash with segfault

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: gdm3 41~rc-0ubuntu2
ProcVersionSignature: Ubuntu 5.13.0-20.20-generic 5.13.14
Uname: Linux 5.13.0-20-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu71
Architecture: amd64
CasperMD5CheckResult: unknown
Date: Mon Nov 1 14:09:49 2021
InstallationDate: Installed on 2018-01-01 (1399 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20171221)
SourcePackage: gdm3
UpgradeStatus: Upgraded to impish on 2019-10-19 (743 days ago)
mtime.conffile..etc.gdm3.custom.conf: 2018-11-01T14:01:52.647430

[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.

[Hassan El Jacifi (waver)]

Hi Daniel,

A crash file have been already uploaded 1st Nov with error tracker id "e5b024f0-3b14-11ec-aedc-fa163e102db1"

[Daniel van Vugt (vanvugt)]

Unfortunately retracing of that crash report failed:

  https://errors.ubuntu.com/oops/e5b024f0-3b14-11ec-aedc-fa163e102db1

Next time it happens again, please repeat the steps in comment #3.

[Hassan El Jacifi (waver)]

Hi Daniel,

Here's the new crash report 36b3082c-40b0-11ec-afad-fa163e102db1.

Thanks

[Daniel van Vugt (vanvugt)]

Thanks. That confirms it is bug 1945061.