CVE-2026-90389

A flaw was found in the Linux kernel. A concurrency issue in the Multiple Device (MD) subsystem's handling of memalloc_noio_save() tokens can occur during concurrent suspend sysfs writes. This allows a task to return to userspace while still within a PF_MEMALLOC_NOIO scope, enabling another task to restore a previously saved token. This could lead to unexpected system behavior or resource management issues, potentially resulting in a denial of service.

This flaw is rated as a Low severity for Red Hat Enterprise Linux because modifying Multiple Device (MD) sysfs attributes requires administrative privileges (root or CAP_SYS_ADMIN). Exploitation relies on inducing a race condition through concurrent suspend writes, which prevents unprivileged local users from triggering the issue under standard operating conditions. Consequently, the impact is confined to memory allocation scope inconsistencies that may lead to a localized denial of service during specific administrative workflows, with no potential for privilege escalation.

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.