A flaw in the Linux kernel’s RDMA/irdma driver involves an Out-of-bounds Write (CWE-791) that permits a user application to invoke rereg_mr on memory regions that were deliberately registered without a valid mkey. This causes the kernel to emit a CQP command with a zero‑initialized mkey value of 0, potentially leading to malformed RDMA operations that could interrupt or degrade system stability. The impact is limited to improper behavior in RDMA communication rather than a guaranteed kernel crash, with a potential for a denial of service if the malformed command results in a failure or resource exhaustion.

The vulnerability resides entirely in the Linux kernel source code. Any system running a kernel compiled from the reported source commits before the patch is affected, regardless of distribution, because the issue is not limited to a particular version range. Users of the irdma RDMA driver on any Linux kernel installation are potentially affected.

The CVSS score of 7.8 classifies the flaw as high severity, and the EPSS score of less than 1% indicates a very low but nonzero exploitation likelihood. The vulnerability is not listed in the CISA KEV catalog, suggesting no publicly documented exploits. It is inferred that the attack vector would be local, requiring an attacker to execute or manipulate a user‑space RDMA application; thus exploitation would be feasible only in environments where untrusted code can invoke RDMA operations.