UBUNTU-CVE-2026-99257: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: gpio: shared: gracefully handle no-device lookup of shared GPIOs We use platform lookup tables for shared GPIOs. This mechanism needs a struct device to work so fwnode-based lookup with no device associated currently causes a NULL-pointer deference. Adding this functionality will require a larger rework and it has never worked anyway so add a check that allows the kernel to gracefully handle this situation with an error ahead of implementing that functionality as a new feature.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
In the Linux kernel GPIO shared-lookup path, add a check for a missing struct device during fwnode-based lookup of shared GPIOs and return an error instead of dereferencing a NULL pointer.
Event History
Frequently Asked Questions
What systems are exposed to this issue?
The affected software list includes Ubuntu Linux kernel packages for the standard, FIPS, AWS, Azure, GCP, Oracle, AWS FIPS, and Azure FIPS variants. The vulnerable path concerns shared GPIO lookup using firmware-node-based lookup when no struct device is associated.
What condition triggers the crash?
The failure occurs when a shared GPIO is looked up through the fwnode-based mechanism without an associated device. Platform lookup tables for shared GPIOs require a struct device, and its absence can lead to a NULL-pointer dereference.
What is the mitigation if an updated kernel cannot be deployed immediately?
Avoid configurations or code paths that perform firmware-node-based lookup of shared GPIOs without an associated struct device. The resolved behavior is to reject that unsupported situation with an error rather than dereferencing a NULL pointer.