This issue involves the Linux kernel’s RDMA/irdma driver allowing re‑registration of memory regions that were intended to be non‑page‑mapped. The driver accepts rereg_mr for those special regions and emits a CQP command with an mkey of 0. The malformed command can disrupt RDMA communication and lead to a denial of service for applications reliant on RDMA. The weakness is an improper input validation coupled with use of uninitialized data.

Any Linux kernel that contains the irdma RDMA driver before the patch that blocks rereg_mr on special memory regions is affected. The vulnerability applies to all distributions whose kernel includes the unpatched source code, regardless of release version. It does not require any special configuration; any user‑space process that can invoke RDMA or rereg_mr calls on such a kernel is at risk.

The CVSS score of 7.8 classifies this as high severity. The EPSS score is less than 1%, indicating a very low but non‑zero likelihood of exploitation. The vulnerability is absent from the CISA KEV catalog, meaning no known public exploits have been documented. The attack vector is local: an attacker must run a user‑space RDMA application on the affected system to exploit the flaw. No network‑exposed input is used, and the flaw does not grant kernel privilege or enable arbitrary code execution.