Linux Kernel EUVD-2026-27626

The vulnerability exists in the Qualcomm PD (Process Domain) mapper driver located in the Linux kernel's SOC (System-on-Chip) subsystem. The issue involves QMI (Qualcomm Message Interface) protocol encoding/decoding for service registry location platform feature requests. Specifically, the servreg_loc_pfr_req_ei structure defines an element information array used to validate and decode incoming QMI messages. The reason field's maximum length was declared as 65 bytes in the element information, but the corresponding servreg_loc_pfr_req structure defines the actual reason field as 81 bytes. This mismatch causes qmi_decode_string_elem to reject valid incoming messages during process daemon crashes, which trigger these requests to the service registry mapper. The root cause is a configuration synchronization failure between two data structures that should define identical field constraints.