CVE-2026-53116

A flaw was found in the Linux kernel's s390/ap driver. A race condition occurs when AP masks are updated, leading to __ap_revise_reserved() accessing the driver_override field without proper locking. This can result in a Use-After-Free (UAF) vulnerability, where memory is accessed after it has been freed. An attacker could potentially exploit this to cause a denial of service or execute arbitrary code.

This vulnerability is rated as Moderate severity because exploitation is restricted to local environments on IBM Z (s390x) architectures and requires concurrent manipulation of Adjunct Processor (AP) bus sysfs attributes. The defect does not affect other CPU architectures, substantially limiting overall exposure across typical enterprise deployments. Furthermore, triggering the race condition demands local access to specific device configuration controls, reducing the risk of spontaneous or remote compromise.

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.