Package: Debian 13.4.0 amd64 /lightdm /cinnamon Dear Debian Developers, When Debian 13.4.0 is installed with all available desktop environments selected during installation and LightDM is chosen as the display manager, logging into the Cinnamon desktop environment fails with "Wrong password" — despite the password being correct. Logging into GNOME on Wayland with the identical credentials succeeds without any issue. This bug has been reported in previous versions (13.2, 13.3) and has not been fixed as of 13.4. Steps to Reproduce: Perform a fresh installation of Debian 13.4.During installation, select all available desktop environments when prompted.Set LightDM as the display manager.Set the same password for both root and the regular user (e.g. a short, simple password).Complete the installation and reboot.At the LightDM login screen, select Cinnamon as the session.Enter the correct user password and attempt to log in.Login fails with the message "Wrong password". The password is correct — the same credentials work when GNOME on Wayland is selected as the session on the same login screen. Additional Information:The issue is session-specific: only Cinnamon is affected; GNOME on Wayland works correctly.The bug is a regression that has persisted across multiple releases: confirmed in Debian 13.2, 13.3, and 13.4.Previous bug reports were filed for 13.2 and 13.3 with no resolution.Display manager: LightDMAffected session: CinnamonWorking session: GNOME on WaylandInstallation method: All desktop environments selected during standard installerPlease investigate why LightDM fails PAM authentication specifically for Cinnamon sessions when multiple desktop environments are installed. This may be related to session configuration files, PAM stack differences between sessions, or a LightDM greeter issue specific to non-Wayland sessions. Erik Palinay
