CVE-2026-43138

What it actually does

The vulnerability permits local users to trigger an unbind operation on a dynamically created GPIO reset device via sysfs bind attributes, causing a use-after-free due to absent device links and permanent device lifetime assumptions.

Why it matters to the business

Local attackers can induce kernel crashes or achieve code execution, resulting in system downtime, data loss, or full host compromise on Linux systems.

How an attack unfolds

An attacker with local access identifies the sysfs entry for the reset device and performs an unbind, freeing the device structure while reset consumers still hold references, leading to use-after-free exploitation.

How to fix it

Apply upstream kernel patches that suppress sysfs bind attributes for the gpio-reset device; rebuild and deploy updated kernels across all affected systems.

How to confirm the fix worked

Inspect the gpio reset driver source for the bind attribute suppression logic and verify that unbind operations are no longer exposed in sysfs for the device.

Typical attack path

1. Obtain local user privileges on the target Linux system
2. Navigate to the sysfs directory for the dynamically created GPIO reset device
3. Write to the unbind attribute to force device removal
4. Leverage the resulting use-after-free for memory corruption or privilege escalation

How to detect it

Review kernel logs and audit trails for sysfs unbind operations targeting gpio-reset devices or unexpected device removal events preceding crashes.

What your security team should do

• Expedite deployment of patched kernels once released
• Limit unprivileged local access on production systems
• Enable kernel hardening features such as memory tagging to reduce UAF exploitability