CVE-2023-54201

In the Linux kernel, the following vulnerability has been resolved:

RDMA/efa: Fix wrong resources deallocation order

When trying to destroy QP or CQ, we first decrease the refcount and potentially free memory regions allocated for the object and then request the device to destroy the object. If the device fails, the object isn't fully destroyed so the user/IB core can try to destroy the object again which will lead to underflow when trying to decrease an already zeroed refcount.

Deallocate resources in reverse order of allocating them to safely free them.

This vulnerability is rated as Moderate severity for Red Hat Enterprise Linux because exploitation requires local access to an Amazon Elastic Fabric Adapter (EFA) RDMA device and relies on an uncommon device-level teardown failure. Under typical cloud deployments, systems without EFA networking hardware attached or without the RDMA subsystem in use remain unaffected. A local user able to trigger an underlying hardware destruction error during queue pair or completion queue release could induce a reference count underflow, resulting in a kernel crash and local denial of service.

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.