Linux Kernel Synaptics RMI4 Electrode Count Misassignment

CVE-2026-80754 is a logic error in the Linux kernel's Synaptics RMI4 touchpad driver where transmitter (TX) electrode counts are incorrectly assigned receiver (RX) values due to copy-paste typos. This affects F55 sensor detection and propagates downstream to F54 diagnostics reporting. On devices with asymmetrical electrode configurations—particularly those with more RX than TX electrodes—the inflated TX count leads to incorrect buffer allocation and diagnostic report sizing. This impacts Linux users running affected kernel versions with Synaptics RMI4 touchpad hardware, potentially causing memory access violations, denial of service, or information disclosure depending on how the oversized buffer is utilized.

While CVE-2026-80754 lacks explicit MITRE ATT&CK mappings, Casky's extended reasoning capabilities would identify this as a potential vector for T1499 (Endpoint Denial of Service) through resource exhaustion via buffer misallocation, or T1005 (Data from Local System) if the oversized buffer exposes adjacent kernel memory. Security practitioners using Casky would observe findings related to code review anomalies, firmware/driver integrity issues, and memory safety violations—patterns consistent with CWE-1025 (Comparison Using Wrong Factors) and CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). Detection would flag suspicious electrode count validation logic and memory allocation discrepancies in kernel driver initialization paths, enabling practitioners to prioritize patching across their Linux infrastructure before exploitation occurs.