CVE-2021-47261

A flaw was found in the Linux kernel's mlx5 InfiniBand driver. When resizing a Completion Queue (CQ) to a larger size, the driver improperly attempts to read queue elements from the original buffer rather than the newly allocated resize buffer. A local user with permissions to perform network queue operations could exploit this vulnerability to trigger an out-of-bounds memory access, resulting in a kernel crash and a denial of service (DoS).

This vulnerability is rated as having Low severity for Red Hat Enterprise Linux because triggering the defect requires systems configured with Mellanox InfiniBand hardware and local access with elevated privileges to execute queue resizing operations. Under typical enterprise configurations lacking Mellanox RDMA devices or with the mlx5_ib driver unutilized, the flaw cannot be exercised. Moreover, the failure mode is restricted to a localized system crash, with no risk of unauthorized data exposure or modification.

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.