CVE-2024-41029

What it actually does

The nvmem cell sysfs attributes bypass permission restrictions set on the main nvmem attribute (such as root_only), allowing unauthorized read access to nvmem data.

Why it matters to the business

Attackers with local access may read sensitive configuration or device data that should be restricted, increasing risk of information disclosure on affected Linux systems.

How an attack unfolds

An attacker with local access identifies nvmem devices where the main attribute restricts access, then directly reads the corresponding cell sysfs attributes which retain broader permissions, bypassing intended controls.

How to fix it

Update the Linux kernel to a version containing commit aa066afaaac32caf2160d58d4e3010ee04421c62 or later to enforce permission masking on cell attributes.

How to confirm the fix worked

Verify the running kernel includes the referenced commit, then confirm that cell sysfs permissions match or are stricter than the main nvmem attribute.

Typical attack path

1. Obtain local shell access on a vulnerable Linux kernel system
2. Locate nvmem devices with restricted main sysfs attributes
3. Access cell-specific sysfs entries to read nvmem contents
4. Extract sensitive data that should have been inaccessible

How to detect it

Review system logs and audit trails for unexpected reads of nvmem-related sysfs paths; correlate with user activity on systems where main attributes were restricted.

What your security team should do

• Prioritize kernel updates on systems exposing nvmem devices
• Audit local access controls and limit unprivileged users where possible
• Monitor for new kernel releases containing the fix