The ad_sigma_delta driver in the Linux kernel’s Industrial I/O system incorrectly handles pending events on registerless analog‑to‑digital converters. When a device lacks a register interface and has no ready‑GPIO active, the driver reads data as a status byte and, in certain configurations, performs a memset with a negative length. This results in a heap buffer overflow that corrupts kernel memory and can be leveraged by an attacker with sufficient input control to gain elevated privileges or crash the system.

The flaw affects the Linux kernel’s ad_sigma_delta driver used by registerless ADC devices, including AD7191, AD7780 (both with and without a power‑down GPIO), and MAX11205. Any Linux kernel build that contains the unpatched driver and interfaces with these devices is vulnerable, regardless of the specific kernel release.

The vulnerability carries a CVSS score of 7.8 and an EPSS score of less than 1 %, and it is not listed in CISA’s Known Exploited Vulnerabilities catalogue. Exploitation would require local access to the compromised ADC or the ability to trigger conversions, making the attack vector likely local. Successful exploitation could corrupt kernel memory and potentially lead to arbitrary code execution or a denial of service.