CVE-2025-40030: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-40030 is a vulnerability discovered in the Linux kernel related to the pinctrl subsystem, specifically involving the handling of return values from pinmuxops::getfunction_name(). The vulnerability was disclosed on October 28, 2025 (NVD).

The vulnerability stems from improper validation of return values from the getfunctionname() callback in struct pinmuxops. While the API contract doesn't explicitly specify it, the generic implementation pinmuxgenericgetfunctionname() can return NULL, which isn't properly handled in pinmuxfuncnameto_selector(), potentially leading to NULL pointer dereference during strcmp() operations. This occurs during normal operations when adding new pinfunctions (NVD). The vulnerability has been assigned a CVSS v3.1 base score of 7.0 with the vector string CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H (Red Hat).

The vulnerability affects multiple versions of the Linux kernel across various distributions, including Red Hat Enterprise Linux versions 7, 8, and 9, along with their real-time kernel variants (Red Hat). The potential impact includes high confidentiality, integrity, and availability risks if successfully exploited.

The vulnerability has been resolved in the Linux kernel through the implementation of proper return value checking in the pinmuxfuncnametoselector() function. A check similar to the one in pinmuxcheckops() has been added to prevent NULL pointer dereferencing (NVD).