CVE-2026-98004

A flaw was found in the Linux kernel's RISC-V IOMMU (Input-Output Memory Management Unit) driver. A local user can exploit this vulnerability to cause a Denial of Service (DoS) on systems running RISC-V architecture. A concurrency issue in how commands are published to the hardware queue allows lock contention to block other processor cores, resulting in a system hang.

This vulnerability is rated as Moderate severity because exploitation requires local access on systems utilizing RISC-V hardware with an active IOMMU, restricting the blast radius to a local denial of service. The concurrency issue in the RISC-V IOMMU command submission logic cannot be triggered remotely, requiring local execution to generate queue contention. Systems deployed on other architectures, such as standard x86_64, aarch64, or s390x, do not load or utilize this hardware-specific driver and remain unaffected.

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.