CVE-2023-53456: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53456 is a vulnerability in the Linux kernel's qla4xxx SCSI driver, discovered and disclosed on October 1, 2025. The vulnerability affects the parsing of nlattrs in three specific functions: qla4xxxsetchapentry(), qla4xxxifacesetparam(), and qla4xxxsysfsddbsetparam(). Each of these functions directly converts nlattr to specific pointer structures without proper length checking (Ubuntu Security).

The vulnerability stems from the direct conversion of nlattr to specific pointer structures without length validation in the qla4xxx driver. When these attributes are not properly validated, a malformed nlattr (for example, with length 0) could trigger an out-of-bounds read, potentially leading to heap data leakage. The issue has been assigned a CVSS v3.1 score of 5.5 with the vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (Red Hat Security).

The vulnerability could result in an out-of-bounds read that leaks heap dirty data, potentially exposing sensitive information from the kernel's memory. This poses a security risk as it could allow local attackers to access unauthorized data (Ubuntu Security).

A fix has been implemented by adding nla_len check before accessing the nlattr data and returning EINVAL if the length check fails. Several Linux distributions have released patches, including Ubuntu 20.04 LTS which has fixed the issue in version 5.4.0-169.187 (Ubuntu Security).