CVE-2026-31426

A flaw was found in the Linux kernel's Advanced Configuration and Power Interface (ACPI) Embedded Controller (EC) subsystem. During the setup of the EC handler, if a probe deferral occurs on specific hardware, the system fails to properly deallocate resources. This oversight creates a use-after-free vulnerability, allowing an unprivileged local attacker to trigger a system crash, resulting in a Denial of Service (DoS). The attacker can exploit this by performing certain system file system (sysfs) reads that interact with EC OpRegion fields.

This affects reduced-hardware EC setups where probe defers after the handler is partially installed. The patch removes handlers on the error path before dropping the EC object. Follow-on AML can be triggered from paths including sysfs-driven configuration reads; impact is at least denial of service via crash, and memory corruption warrants manual review for any broader confidentiality or integrity claim.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.