CVE-2026-53164

A flaw was found in the Linux kernel's input/output memory management unit (IOMMU) Direct Memory Access (DMA) subsystem, specifically within the software IOMMU bounce buffer (SWIOTLB) mechanism. This vulnerability occurs when the system attempts to map a zero-length memory region, which can be triggered by certain Thunderbolt NVMe drives passing unaligned memory buffers. This improper handling can lead to corruption of memory mappings, potentially causing system instability or a denial of service (DoS).

This vulnerability is rated as Moderate severity because triggering the issue requires local user access or specific hardware conditions to issue unaligned passthrough operations, and the overall impact is confined to a denial of service. Under typical Red Hat Enterprise Linux deployments, ordinary storage operations do not trigger this error unwind condition in the bounce buffering layer unless forced by specialized external storage controllers or diagnostic tooling. Furthermore, earlier platform releases such as Red Hat Enterprise Linux 8 do not contain the affected code path.

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.