Ubuntu
gnome-flashback package

gnome-flashback libscreensaver use wrong session path on ubuntu 20.04

Bug #1894213 reported by Valentyna on 2020-09-04

This bug affects 2 people

	Status	Importance	Assigned to
GNOME Flashback	Fix Released	Unknown	auto-gitlab.gnome.org-gnome-gnome-flashback-- #67
gnome-flashback (Ubuntu)	Fix Released	Undecided	Unassigned
Focal	Fix Released	Undecided	Dmitry Shachnev

Bug Description

[Impact]

logind sessions have string IDs. When constructing the D-Bus path of a session, systemd uses bus_label_escape() function. That function escapes everything that is not a-zA-Z0-9 with a '_' plus two hexadecimal digits. It also escapes 0-9 if it's the first character. For example, '6' which is (char)0x36 becomes "_36".

GNOME Flashback did not support this escaping logic, so unlocking did not work in some cases.

[Test Case]

1. Lock screen.
2. Press button "Switch user...".
3. Type username and password.
4. Screensaver does not unlock the current session and shows unlock dialog.

[Where problems could occur]

Potential problems will be related to screensaver code. For example, if something goes wrong with systemd D-Bus interface, it will not work.

[Other Info]

Original description:

My OS:
lsb_release -rd
Description: Ubuntu 20.04.1 LTS
Release: 20.04

If I lock my screen and then press button "Switch User..." and again type my login and pass, screensaver does not unlock my current session and shows unlock dialog. This is because of incorrect path of session in libscreensaver/gf-listener.c.
To fix this problem should add "_3" to path. I create a patch which fixes problem.

See original description

Tags:

Revision history for this message

Valentyna (valia0906) wrote on 2020-09-04:

Patch, which fixes a problem. Edit (407 bytes, text/plain)

summary:

- gnome-flashback libscreensaver use wrong session on path 20.04
+ gnome-flashback libscreensaver use wrong session path on ubuntu 20.04

Revision history for this message

Alberts Muktupāvels (muktupavels) wrote on 2020-09-04:

Please open merge request upstream - https://gitlab.gnome.org/GNOME/gnome-flashback/-/merge_requests.

What is "_3"?

Revision history for this message

Launchpad Janitor (janitor) wrote on 2020-09-04:

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in gnome-flashback (Ubuntu):
status:	New → Confirmed

Revision history for this message

Valentyna (valia0906) wrote on 2020-09-04:

I`ve arready create merge request https://gitlab.gnome.org/GNOME/gnome-flashback/-/merge_requests/33

I`ve seen in DBus org.freedesktop.login1.Manager ListSessions method displays info about each session and in the end is session path ex. '/org/freedesktop/login1/session/_36'. If I open org.freedesktop.login1 I saw the same path for my session '/org/freedesktop/login1/session/_36' where can I go see Properties like id/TTY and run such Methods like Lock()/Unlock() and so on.

I don`t know how this "_3" is attached to path.

Revision history for this message

Alberts Muktupāvels (muktupavels) wrote on 2020-09-04:

Thanks!

Revision history for this message

Alberts Muktupāvels (muktupavels) wrote on 2020-09-04:

Fix will be available in 3.36.5.

gnome-3-36: https://gitlab.gnome.org/GNOME/gnome-flashback/-/commit/06b8ed79efe8029eb522380a11f837cc32a4ae15
master: https://gitlab.gnome.org/GNOME/gnome-flashback/-/commit/157f26ad4afd2d79b99fa0dea4166fd1f6d5829a

Revision history for this message

Dmitry Shachnev (mitya57) wrote on 2020-12-08:

This is fixed in Groovy. I will prepare a fix for Focal.

description:	updated
Changed in gnome-flashback (Ubuntu):
status:	Confirmed → Fix Released
Changed in gnome-flashback (Ubuntu Focal):
assignee:	nobody → Dmitry Shachnev (mitya57)

Revision history for this message

Brian Murray (brian-murray) wrote on 2020-12-08: Please test proposed package

Hello Valentyna, or anyone else affected,

Accepted gnome-flashback into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/gnome-flashback/3.36.5-0ubuntu1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Changed in gnome-flashback (Ubuntu Focal):
status:	New → Fix Committed
tags:	added: verification-needed verification-needed-focal

Revision history for this message

Valentyna (valia0906) wrote on 2020-12-09:

The problem is fixed.Thank you.

Revision history for this message

Valentyna (valia0906) wrote on 2020-12-09:

#10

tag verification-done-focal

tags:

added: verification-done-focal
removed: verification-needed verification-needed-focal

Revision history for this message

Launchpad Janitor (janitor) wrote on 2020-12-15:

#11

This bug was fixed in the package gnome-flashback - 3.36.5-0ubuntu1

---------------
gnome-flashback (3.36.5-0ubuntu1) focal; urgency=medium

  * New upstream bugfix release (LP: #1907275).
    - screensaver: get session path from logind manager (LP: #1894213).
  * Drop fi-translation.patch, included in the new release.

-- Dmitry Shachnev <email address hidden> Tue, 08 Dec 2020 19:00:22 +0300

Changed in gnome-flashback (Ubuntu Focal):
status:	Fix Committed → Fix Released

Revision history for this message

Brian Murray (brian-murray) wrote on 2020-12-15: Update Released

#12

The verification of the Stable Release Update for gnome-flashback has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

Bug Watch Updater (bug-watch-updater) on 2022-05-20