CVE-2026-72305

A Moderate security impact flaw was found in the Linux kernel's VDUSE (vDPA Device in Userspace) implementation, which is included in the Red Hat Enterprise Linux and Red Hat In-Vehicle OS kernels. VDUSE maps DMA bounce pages to userspace, but the bouncing is not necessarily page-aligned and the bounce pages were not zeroed on allocation, so unused bytes in a mapped page may contain stale kernel memory from prior use. As a result, a local user with access to the VDUSE device interface can read kernel information that should not be exposed. The issue is not network reachable, provides no write primitive, and affects confidentiality only. Red Hat Enterprise Linux 9 (the 9.6, 9.8, and 9.9 kernel and kernel-rt streams), Red Hat Enterprise Linux 10, and Red Hat In-Vehicle OS 2 are affected because they contain the MMU-based software IOTLB VDUSE implementation backported into RHEL 9.5 and later. Red Hat Enterprise Linux 6, 7, and 8, and the RHEL 9.2 and 9.4 streams, are not affected because the vulnerable code is not present. Fixes for the affected streams are currently deferred to a future update; the residual risk is limited to local disclosure of stale kernel memory by a user who already has access to the VDUSE device interface.