'swipe finger' in login interface disappear and show up periodically

[Bin Li]

After upgrade gnome-shell from 3.36.7-0ubuntu0.20.04.1 to 3.36.9-0ubuntu0.20.04.1, I met this issue. We took a short video for this issue.

[Bin Li (binli)]

From the log, it will repeatedly report below errors. Looks like the The gdm-session-worker was called when fprintd return's failure. Looks related to latest change in gnome-shell.

- Show errors on fingerprint failures and limit retries (LP: #1865838)

Jun 15 06:48:47 Lynx-4 gdm3[1022]: Freeing conversation 'gdm-fingerprint' with active job
Jun 15 06:48:48 Lynx-4 gdm-password][1986]: pam_unix(gdm-password:auth): Couldn't open /etc/securetty: No such file or directory
Jun 15 06:48:48 Lynx-4 kernel: usb 3-3: reset full-speed USB device number 2 using xhci_hcd
Jun 15 06:48:49 Lynx-4 upowerd[1195]: treating change event as add on /sys/devices/pci0000:00/0000:00:14.0/usb3/3-3
Jun 15 06:48:49 Lynx-4 upowerd[1195]: treating change event as add on /sys/devices/pci0000:00/0000:00:14.0/usb3/3-3
Jun 15 06:48:49 Lynx-4 fprintd[1496]: identify has failed: 114
Jun 15 06:48:49 Lynx-4 fprintd[1496]: Device reported an error during identify: Unexpected result from device 114
Jun 15 06:48:49 Lynx-4 gdm-session-worker[1987]: free(): double free detected in tcache 2

[Bin Li (binli)]

It will retry about 70 times, and don't disappear, wait for a while to lock screen, then login again, I found there are no 'swipe finger' text.

[Bin Li (binli)]

After login with username and password, I found the gdm-session-worker is crashed.

[Daniel van Vugt (vanvugt)]

I can't figure out which crash that is. Please upload the crash file using 'ubuntu-bug' or 'apport-cli'.

[Daniel van Vugt (vanvugt)]

Oh yes, the message in comment #2:

gdm-session-worker[1987]: free(): double free detected in tcache 2

matches:

https://errors.ubuntu.com/problem/476b07edafb4eaa68c811cb00291075695ac7376

[Daniel van Vugt (vanvugt)]

^^^
That's being tracked in bug 1933068, separate to this bug in case it's not the main issue here.