CVE-2021-47646

A flaw was found in the Linux kernel's Block Layer BFQ I/O scheduler. A Use-After-Free (UAF) vulnerability could be triggered by a specific commit related to queue merges. This flaw could lead to a system crash, resulting in a Denial of Service (DoS).

This vulnerability is rated as Moderate because it requires local access to trigger, and successful exploitation results exclusively in a denial of service (system crash) without directly impacting data confidentiality or integrity. Under standard Red Hat Enterprise Linux configurations, BFQ is not the default I/O scheduler, significantly reducing exposure across typical deployments. Systems are only susceptible if the BFQ scheduler is explicitly configured for one or more block devices and subjected to concurrent queue operations.

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.