Installing or removing apps through snap-store launches another gdm session
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
gdm3 (Ubuntu) |
Fix Released
|
High
|
Ghadi Rahme | ||
Jammy |
Fix Released
|
High
|
Ghadi Rahme | ||
Kinetic |
Won't Fix
|
Low
|
Unassigned | ||
Lunar |
Fix Released
|
Low
|
Ghadi Rahme | ||
Mantic |
Fix Released
|
High
|
Ghadi Rahme |
Bug Description
gdm3 version: 42.0-1ubuntu7.
Ubuntu version: Ubuntu 22.04.2 LTS
[Description]
Installing or removing snap packages through NICE DCV on AWS will cause the user to be kicked out of their session. The issue happens on machines running nvidia GPUs (passed through to a VM) with the GRID driver installed as well as the normal nvidia driver.
[Steps to reproduce]
Simply install or remove any snap through the snap store will trigger the issue, for example:
$ snap install skype
also running any of the following commands will also trigger the issue:
$ snap connect skype:opengl :opengl
$ snap disconnect skype:opengl :opengl
$ snap connect skype:camera :camera
$ snap disconnect skype:camera :camera
After further investigation I was able to pin down the issue to udev and could reproduce the issue by running the following command:
$ sudo udevadm trigger --parent-
where "/sys/devices/
A more generic way of triggering the issue would be running:
$ sudo udevadm trigger
[Solution]
I have investigated the issue and discovered that it lies within GDM3 in the "udev_is_settled" function (daemon/
In the case where the udev is settled the line "g_clear_
I have written a patch that fixes this issue by making sure the function "g_clear_
[possible regressions]
Excessive clearing of the signal handler might cause a case where it is not being re-initialized the next time it is needed.
[Base test plan]
This test plan is to make sure the issue listed in the description section is fixed.
1. Create a new nvidia accelerated VM instance on AWS with NICE DCV and the GRID driver (or normal driver) installed. Make sure the GPU is being fully passed through to the instance (do not slice the GPU).
2. Access the instance using the NICE DCV client and login.
3. Install any snap package (E.g $ snap install skype).
4. Verify there are no new sessions being launched with the user being gdm.
$ sudo loginctl
Also make sure that you don't get logged out of your own session.
5. Repeat step 4 while running the following command as well:
$ sudo udevadm trigger
6. If the current session stays active and no new sessions spawn while performing step 3 or 5, the test succeeded.
[Extra tests]
This test plan is a sanity check to make sure no regressions have been created.
1. Login to the session
2. Run a few applications (E.g: Nautilus, gedit, terminal, firefox, skype, libreoffice, mpv, vlc...) and use some on the built in features (E.g: the launcher, search...)
3. Switch sessions without terminating the current one.
4. Login as a separate user and repeat step 2
5. Go back to the first session and make sure everything behaves as expected
6. Switch to init 3:
$ init 3
and go back to init 5 afterwards:
$ init 5
7. If no issues were found, the test succeeded.
Changed in gdm3 (Ubuntu Jammy): | |
importance: | Undecided → High |
assignee: | nobody → Ghadi Rahme (ghadi-rahme) |
status: | New → In Progress |
Changed in gdm3 (Ubuntu Lunar): | |
importance: | Undecided → High |
assignee: | nobody → Ghadi Rahme (ghadi-rahme) |
status: | New → In Progress |
Changed in gdm3 (Ubuntu Mantic): | |
milestone: | ubuntu-22.04.2 → mantic-updates |
Changed in gdm3 (Ubuntu Jammy): | |
milestone: | none → ubuntu-22.04.3 |
Changed in gdm3 (Ubuntu Lunar): | |
milestone: | none → lunar-updates |
Changed in gdm3 (Ubuntu Mantic): | |
status: | In Progress → Fix Committed |
Changed in gdm3 (Ubuntu Lunar): | |
status: | In Progress → Fix Committed |
description: | updated |
description: | updated |
tags: |
added: verification-done-lunar removed: verification-needed-lunar |
tags: |
added: verification-done removed: verification-needed |
The attachment "gdm3-logout- patch.debdiff" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.
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