Public bug reported:
Title:
Fingerprint authentication intermittently fails after Logout followed by
closing the laptop lid and Suspend/Resume
Summary:
Fingerprint authentication intermittently fails at the GDM login screen after
logging out, closing the laptop lid, and leaving the laptop suspended for
several hours.
The fingerprint reader works normally after reboot and also works
reliably when logging out and immediately logging back in.
The problem appears to be intermittent and seems related to the
sequence/timing involving Logout, closing the lid, and Suspend/Resume.
System information:
- Ubuntu 24.04
- Dell Pro 15 Essential PV15250
- Manufacturer: Dell Inc.
- Fingerprint reader: Elan Microelectronics Corp. ELAN:ARM-M4
- USB ID: 04f3:0c88
Installed versions:
- gdm3: 46.2-1ubuntu1~24.04.9
- fprintd: 1.94.3-1
- libfprint-2-2: 1:1.94.7+tod1-0ubuntu5~24.04.8
- libfprint-2-tod1:amd64: 1:1.94.7+tod1-0ubuntu5~24.04.8
- libpam-fprintd:amd64: 1.94.3-1
Steps to reproduce / observed behavior:
1. Log in normally.
2. At the end of the session, select "Log Out".
3. GDM remains active and the login screen is available after moving the mouse,
although the screen initially appears black.
4. Close the laptop lid.
5. The laptop suspends.
6. Leave it suspended for several hours.
7. Open the lid and attempt to authenticate at the GDM login screen using the
fingerprint reader.
Expected behavior:
The fingerprint reader should be available at the GDM login screen and placing
a registered finger on the reader should initiate fingerprint authentication.
Actual behavior:
Intermittently, the fingerprint reader does not respond at all. There may be no
error message in the GDM interface, and placing a finger on the reader appears
to do nothing.
Authentication with the password still works normally.
Important observations from testing:
- After a reboot, fingerprint authentication at GDM has consistently worked.
- Logging out and immediately logging back in with a fingerprint has worked.
- Logging out and waiting before closing the lid has also worked in at least
one controlled test.
- A test where the laptop was locked/suspended without logging out and the VPN
remained connected initially failed, but a later similar test succeeded.
Therefore I do not currently have evidence that the VPN is related to the
problem.
- The problem appears to be associated with the combination of Logout + closing
the lid + Suspend/Resume, but the exact trigger has not yet been isolated.
- The laptop is normally left logged out overnight and the lid is closed.
- When the problem occurs after several hours, fingerprint authentication may
produce no visible response at all.
- In one successful test, I waited more than one minute between reaching the
GDM login screen after Logout and closing the lid, and fingerprint
authentication worked the following morning. This is only an observation at
this point, not a confirmed workaround.
Relevant journal information:
During a failed attempt after approximately 8 hours with the laptop
suspended, fprintd was running:
$ systemctl status fprintd --no-pager
● fprintd.service - Fingerprint Authentication Daemon
Loaded: loaded (/usr/lib/systemd/system/fprintd.service; static)
Active: active (running) since Tue 2026-09-15 23:00:42 IDT; 8h ago
Docs: man:fprintd(1)
Main PID: 841795 (fprintd)
Tasks: 6 (limit: 18535)
Memory: 2.8M (peak: 3.9M)
CPU: 84ms
CGroup: /system.slice/fprintd.service
└─841795 /usr/libexec/fprintd
The relevant fprintd journal for the period was:
$ journalctl -u fprintd --since "2026-09-15 23:00:40" --until
"2026-09-16 07:57:00" -o cat
Starting fprintd.service - Fingerprint Authentication Daemon...
Started fprintd.service - Fingerprint Authentication Daemon.
Device reported an error during verify: Cannot run while suspended.
fprintd.service: Deactivated successfully.
The service started at approximately 23:00:42, which was the time Logout
was performed and the GDM login screen was reached before closing the
laptop lid.
There is also evidence that the laptop entered and exited suspend
normally. For example, during an earlier test:
2026-09-14 08:37:12:
systemd-logind: Lid closed.
systemd-logind: Suspending...
kernel: PM: suspend entry (s2idle)
2026-09-14 08:37:19:
kernel: PM: suspend exit
systemd-sleep: System returned from sleep operation 'suspend'
systemd-logind: Operation 'suspend' finished
During the same period, fprintd was activated after resume:
2026-09-14 08:37:19:
dbus-daemon: Activating via systemd: service name='net.reactivated.Fprint'
unit='fprintd.service'
systemd: Starting fprintd.service - Fingerprint Authentication Daemon...
systemd: Started fprintd.service - Fingerprint Authentication Daemon.
A later suspend attempt produced:
2026-09-14 08:37:48:
fprintd: Device reported an error during verify: Cannot run while suspended.
and:
gdm-fingerprint: pam_fprintd(gdm-fingerprint:auth): ReleaseDevice failed:
Release failed with error: The device is still busy with another operation,
please try again later.
This suggests that there may be an interaction between
GDM/pam_fprintd/fprintd and the suspend/resume lifecycle of the
fingerprint device.
Fingerprint hardware:
$ lsusb | grep -Ei
'finger|fprint|validity|synaptics|goodix|elan|egis|elan'
Bus 001 Device 003: ID 04f3:0c88 Elan Microelectronics Corp. ELAN:ARM-M4
Package information:
$ dpkg -l | grep -E 'gdm3|fprintd|libfprint'
ii fprintd 1.94.3-1
ii gdm3 46.2-1ubuntu1~24.04.9
ii libfprint-2-2
1:1.94.7+tod1-0ubuntu5~24.04.8
ii libfprint-2-tod1:amd64
1:1.94.7+tod1-0ubuntu5~24.04.8
ii libpam-fprintd:amd64 1.94.3-1
Hardware:
$ sudo dmidecode -s system-manufacturer
Dell Inc.
$ sudo dmidecode -s system-product-name
Dell Pro 15 Essential PV15250
Question / suspected area:
Could there be a race condition or lifecycle issue involving GDM,
pam_fprintd, fprintd/libfprint, and the fingerprint device when the user
logs out, the laptop lid is closed shortly afterwards, and the system
enters suspend?
In particular, the journal contains:
"Device reported an error during verify: Cannot run while suspended."
and:
"ReleaseDevice failed: The device is still busy with another operation"
The issue is intermittent, so I would appreciate guidance on whether
this is a known issue and whether there are recommended configuration
changes, package updates, or debugging steps that could help identify or
resolve it.
The problem does not appear to be related to the fingerprint hardware
itself, since fingerprint authentication works after reboot and in
several other Logout/login tests.
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: fprintd 1.94.3-1
ProcVersionSignature: Ubuntu 6.8.0-139.139-generic 6.8.12
Uname: Linux 6.8.0-139-generic x86_64
ApportVersion: 2.28.3-0ubuntu0.1
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Wed Sep 16 12:18:14 2026
DistributionChannelDescriptor:
# This is the distribution channel descriptor for the OEM CDs
# For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
canonical-oem-somerville-jammy-amd64-20220504-33
SourcePackage: fprintd
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: fprintd (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug noble
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https://bugs.launchpad.net/bugs/2167445
Title:
Fingerprint authentication intermittently fails after Logout followed
by closing the laptop lid and Suspend/Resume
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