CVE-2026-72172

A flaw was found in the Linux kernel. When Direct Access (DAX) memory is hotplugged, certain internal memory structures (struct pages) may not be fully initialized. This uninitialized state can lead to unexpected system behavior or crashes, potentially resulting in a denial of service.

DAX memory hotplug into an unoccupied subsection of an early section can reuse an unoptimized boot memmap while compound page accounting assumes vmemmap optimization. This can leave remaining tail struct pages for ZONE_DEVICE uninitialized and later cause unexpected behavior or kernel crashes when those page metadata entries are used. For the CVSS the PR:L is used for the paranoid score because some deployments may delegate DAX or memory management operations to a local service account or reduced capability administrator, although typical systems require full administrative control. The issue is not network reachable and requires local control over DAX memory hotplug or a closely related management path. Impact is at least local denial of service via kernel crash and in worst case may allow limited confidentiality or integrity impact due to corrupted or uninitialized memory metadata, so it should be reviewed manually.

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.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.