Ubuntu 26.04 LTS – GNOME login loop after NVIDIA driver update – Fix & Prevention

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Graphical login returns to greeter repeatedly, blocking desktop access.

Environment & Reproduction

Often follows proprietary driver updates or mismatched kernel module state.

systemctl status gdm3
ubuntu-drivers devices
nvidia-smi 2>/dev/null || true

Root Cause Analysis

Display manager starts but graphics session fails due to driver/library mismatch or Wayland incompatibility.

Quick Triage

Collect gdm, kernel, and Xorg/Wayland errors quickly.

journalctl -u gdm3 -n 120 --no-pager
journalctl -b -p err --no-pager | tail -n 120
lsmod | grep nvidia

Step-by-Step Diagnosis

Confirm installed driver packages and DKMS build success for current kernel.

dkms status
uname -r
dpkg -l | grep -E 'nvidia-driver|nvidia-dkms'

Solution – Primary Fix

Install Ubuntu-recommended driver and rebuild initramfs.

sudo ubuntu-drivers autoinstall
sudo update-initramfs -u
sudo systemctl restart gdm3

Solution – Alternative Approaches

Temporarily force Xorg session or use open driver for recovery.

sudo sed -i 's/^#WaylandEnable=false/WaylandEnable=false/' /etc/gdm3/custom.conf
sudo apt install -y xserver-xorg-video-nouveau

Verification & Acceptance Criteria

Desktop session starts successfully and remains stable across reboot.

systemctl is-active gdm3
loginctl
nvidia-smi 2>/dev/null || true

Rollback Plan

Purge problematic driver package and return to prior known-good version if needed.

sudo apt purge -y 'nvidia-*'
sudo apt autoremove -y
sudo reboot

Prevention & Hardening

Pin validated GPU driver versions and test kernel-driver combos before rollout.

ubuntu-drivers devices
apt-cache policy nvidia-driver-* | head -n 80

Related Errors & Cross-Refs

Often appears with Secure Boot module signing issues and mismatched display-manager settings.

Related tutorial: View the step-by-step tutorial for Ubuntu 26.04 LTS.

View all Ubuntu 26.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu graphics driver and desktop session troubleshooting documentation.