<html><head><style type="text/css">.style1 {font-family: "Times New Roman";}</style></head><body>
<div dir="ltr"><div>Package: fprintd<br></div><div>Version: 1.94.5-2 <br></div><div>Severity: normal<br><br>When a fingerprint device is present but no fingerprints are enrolled for the<br>user, pam_fprintd causes GDM greeter instability at login. The symptom is a<br>visible black flash on the login screen. Greeter with user list shows -> flash to tty -> flash to user list again. Then I can log in.<br><br>On kernel 6.12.63, the GDM greeter restarts (two gnome-shell instances spawn<br>in sequence). On kernel 6.12.73, it escalates to a full Xwayland crash that<br>takes down the entire GDM greeter session.<br><br>The root cause appears to be pam_fprintd returning a failure rather than<br>PAM_IGNORE when no fingerprints are enrolled, causing GDM to restart or crash<br>its greeter compositor.<br><br>Hardware: Intel Meteor Lake (Goodix MOC Fingerprint Sensor)<br>Display server: Wayland (GDM/GNOME Shell 48.7)<br>OS: Debian trixie<br><br>Workaround: disable fingerprint authentication in pam-auth-update.<br><br>Confirmed with:<br> fprintd-list jan<br> → "User jan has no fingers enrolled for Goodix MOC Fingerprint Sensor"<br><br>-- Logs from kernel 6.12.63 (greeter restart) --<br><br>Mar 08 16:28:47 sarao systemd[1]: Starting gdm.service - GNOME Display Manager...<br>Mar 08 16:28:47 sarao systemd[1]: Started gdm.service - GNOME Display Manager.<br>Mar 08 16:28:47 sarao gdm-launch-environment][1730]: pam_unix(gdm-launch-environment:session): session opened for user Debian-gdm(uid=113) by (uid=0)<br>Mar 08 16:28:47 sarao gnome-shell[1991]: Running GNOME Shell (using mutter 48.7) as a Wayland display server<br>Mar 08 16:28:47 sarao gnome-shell[1991]: Added device '/dev/dri/card0' (i915) using atomic mode setting.<br>Mar 08 16:28:48 sarao gnome-shell[1991]: Using public X11 display :1024, (using :1025 for managed services)<br>Mar 08 16:28:48 sarao gnome-shell[1991]: Using Wayland display name 'wayland-0'<br>Mar 08 16:28:50 sarao gnome-shell[2836]: Running GNOME Shell (using mutter 48.7) as a Wayland display server<br>Mar 08 16:28:50 sarao gnome-shell[2836]: Added device '/dev/dri/card0' (i915) using atomic mode setting.<br>Mar 08 16:28:50 sarao gnome-shell[2836]: Using public X11 display :1024, (using :1025 for managed services)<br>Mar 08 16:28:50 sarao gnome-shell[2836]: Using Wayland display name 'wayland-0'<br>Mar 08 16:28:47 sarao gdm-launch-environment][2799]: pam_unix(gdm-launch-environment:session): session opened for user Debian-gdm(uid=113) by (uid=0)<br>Mar 08 16:28:53 sarao gdm-fingerprint][3288]: gkr-pam: no password is available for user<br><br>-- Logs from kernel 6.12.73 (Xwayland crash) --</div><div><br>Mar 08 16:28:47 sarao systemd[1]: Starting gdm.service - GNOME Display Manager...<br>Mar 08 16:28:47 sarao systemd[1]: Started gdm.service - GNOME Display Manager.<br>Mar 08 16:28:47 sarao gdm-launch-environment][1730]: pam_unix(gdm-launch-environment:session): session opened for user Debian-gdm(uid=113) by (uid=0)<br>Mar 08 16:28:47 sarao gnome-shell[1991]: Running GNOME Shell (using mutter 48.7) as a Wayland display server<br>Mar 08 16:28:47 sarao gnome-shell[1991]: Added device '/dev/dri/card0' (i915) using atomic mode setting.<br>Mar 08 16:28:48 sarao gnome-shell[1991]: Using public X11 display :1024, (using :1025 for managed services)<br>Mar 08 16:28:48 sarao gnome-shell[1991]: Using Wayland display name 'wayland-0'<br>Mar 08 16:28:50 sarao gnome-shell[2836]: Running GNOME Shell (using mutter 48.7) as a Wayland display server<br>Mar 08 16:28:50 sarao gnome-shell[2836]: Added device '/dev/dri/card0' (i915) using atomic mode setting.<br>Mar 08 16:28:50 sarao gnome-shell[2836]: Using public X11 display :1024, (using :1025 for managed services)<br>Mar 08 16:28:50 sarao gnome-shell[2836]: Using Wayland display name 'wayland-0'<br>Mar 08 16:28:47 sarao gdm-launch-environment][2799]: pam_unix(gdm-launch-environment:session): session opened for user Debian-gdm(uid=113) by (uid=0)<br>Mar 08 16:28:53 sarao gdm-fingerprint][3288]: gkr-pam: no password is available for user<br><br></div><br><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div>Jan Groenewald</div><div>DevOps Engineer</div><div>NRF-SARAO</div><div><br></div></div></div></div>
<br><br><p style="font-family: Verdana; font-size:10pt; color:#666666;"><b>Disclaimer</b></p>
<p style="font-family: Verdana; font-size:8pt; color:#666666;">
The information contained in this communication from the sender is confidential. It is intended solely for use by the recipient and others authorized to receive it. If you are not the recipient, you are hereby notified that any disclosure, copying, distribution or taking action in relation of the contents of this information is strictly prohibited and may be unlawful.<br>
</p>
</body></html>