CVE-2026-80523

A flaw was found in the Linux kernel. The HDMA (Hardware Direct Memory Access) clock, responsible for the internal TCM (Tightly Coupled Memory) access path of the X100 RISC-V core, was not set as critical. This oversight allows the clock to be shut off, which can lead to a system hang, for example, when a vector instruction access generates a page fault. This vulnerability could result in a denial of service.

A low impact flaw was found in the Linux kernel Spacemit K3 clock driver, affecting the Red Hat Enterprise Linux 10.3 and 10.4 kernels and the Red Hat In-Vehicle OS 2.0 and 2.1 kernels. The HDMA clock, which serves the internal TCM access path of the X100 RISC-V core, was not marked as critical, so the kernel clock framework can shut it off. Once this clock is gated off, CPU activity that uses that access path, for example a vector instruction access that generates a page fault, can hang the Linux system, resulting in a denial of service. Only availability is affected; there is no impact on confidentiality or integrity. All other Red Hat Enterprise Linux kernel streams are not affected because the vulnerable Spacemit K3 clock driver code is not present in their builds. Red Hat rates this flaw Low impact (CVSS 5.5, MODERATE severity), which is lower than the upstream CVE.org rating of 7.1 (IMPORTANT), because triggering the hang requires running code locally on an affected Spacemit K3-based system and the consequence is a denial of service limited to that system. The fix for the affected streams is currently deferred to a future release; until it is delivered, affected systems retain a residual risk of a system hang on Spacemit K3-based hardware.

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 do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.