CVE-2025-21966

A flaw was found in the Linux kernel's dm-flakey driver. An incorrect parameter is passed during block input/output (I/O) request initialization when using the optional corrupt_bio_byte testing feature. A local user with administrative privileges could trigger this flaw when configuring storage device tables, causing memory corruption and a Denial of Service (DoS) through a system crash.

This vulnerability is rated as Moderate severity for Red Hat Enterprise Linux because exploitation requires elevated privileges (such as root or CAP_SYS_ADMIN) to configure device-mapper tables, restricting the attack vector to administrative users. The issue exists within dm-flakey, a non-default testing target utilized primarily for simulating storage hardware errors during diagnostic or filesystem testing. Because the affected corrupt_bio_byte parameter is an optional setting rarely deployed in standard production environments, the overall operational risk remains low.

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.