In the Linux kernel, a flaw in the md/raid1 subsystem causes reference‑counting leaks when write requests fail. Missing calls to md_write_end() and the failure to free barrier references result in unreleased memory and resource handles. These accumulate over time, potentially exhausting kernel memory and destabilizing the RAID1 device, which can lead to a denial of service.

The affected product is the Linux kernel’s md/raid1 module. The fix applies to all kernel versions that contain the pre‑existing md/raid1 code; the patch is incorporated in the upstream commit referenced by the advisory. Because no explicit version range is listed, any deployment using an earlier kernel should verify the presence of the commit or upgrade to a kernel that includes the patch.

The CVSS score is 7.1, indicating a high severity vulnerability; the EPSS score is below 1%, implying a low exploitation probability, and the vulnerability is not listed in CISA’s KEV catalog. Exploitation would still require the ability to trigger repeated write failures against a RAID1 array, which generally demands local or privileged access, as inferred from the need to generate write paths that hit the failure branches. Therefore the risk remains primarily local or privileged, with the potential to cause resource exhaustion and system instability. Because the flaw is a leakage rather than code execution, the main countermeasure is to apply the vendor patch as soon as possible.