Dennis HilkLinux Fix LabDE

Graphics, GPU & Display

NVIDIA module is rejected by signature enforcement

A signed-module policy can block NVIDIA after a kernel or DKMS update; check trust and build status before changing Secure Boot settings.

Editorial source review: Start with the evidenceShare this guide
On this page
  1. Symptoms & scope
  2. Possible causes
  3. Diagnose safely
  4. Evidence-guided next steps
  5. References & review
  6. Related problems

Symptoms & scope

  • Fallback graphics is active after installing a driver.
  • Loading nvidia reports Key was rejected by service or a signing-related denial.

Relevant environment

NVIDIA on systems enforcing kernel module signatures, often with UEFI Secure Boot and distribution shim/MOK enrollment.

Recognizable messages (synthetic examples)
modprobe: ERROR: could not insert 'nvidia': Key was rejected by service

Inspect trusted signing and enrollment. A tainting warning that still permits loading is intentionally excluded.

Possible causes

These are possible explanations, not a confirmed diagnosis. Several independent faults can coexist.

  • A DKMS-built module may be unsigned or signed by a key not enrolled in the kernel’s trust path.
  • An enrollment step may be incomplete; a permissive verification warning is different from an enforced rejection.

Diagnose safely

Run one command at a time in the relevant session. Read the explanation first. Uppercase placeholders need your own values; tools and privileges vary by distribution. These commands are displayed here and never executed by the website.

Check 1

Read UEFI Secure Boot state on a shim/MOK system; mokutil must be installed. This does not change key enrollment.

mokutil --sb-state

Interpret the result: Enabled Secure Boot supports checking module trust but does not prove why NVIDIA failed; other kernels can enforce signatures independently.

Check 2

Read the signer of the installed module for the running kernel; it may need the correct module package installed.

modinfo -F signer nvidia

Interpret the result: An empty signer suggests no recorded signature. A nonempty signer does not establish that its key is trusted or that this exact module loaded.

Evidence-guided next steps

Use a distribution-supported signed module

If the driver package lacks a trusted module for the selected kernel, install the distribution’s supported signed module package or its documented DKMS signing setup. Confirm successful build and enrollment before reboot.

Precautions: Choose the branch that supports the actual GPU and kernel. Do not use an unsigned downloaded installer as a substitute for the existing package system.

Recovery / rollback: Boot the previous supported kernel and matching signed module if the new package cannot load.

Did this solution help you?

Share this solution#

Complete the documented key enrollment

If DKMS uses a locally generated signing key, follow the distribution’s MOK enrollment process and approve that known key in the firmware enrollment screen. Then verify module loading after a normal reboot.

Precautions: Keep recovery media and any disk-encryption recovery secret available before changing boot trust. Never enroll an unidentified key.

Recovery / rollback: Return to the previously trusted signed boot path; remove only the newly enrolled key via the documented process if it was added incorrectly.

Did this solution help you?

Share this solution#

References & review

This guide was prepared from primary project or distribution sources and reviewed on the date shown. This is an editorial source check, not evidence that a fix was reproduced on your hardware. Diagnostic log examples are synthetic fixtures. Version-dependent details must be checked against your installed release.