CVE-2026-90137: Undefined Security Weakness

In the Linux kernel, the following vulnerability has been resolved:

platform/x86: hp-bioscfg: fix password encoding bounds check

The password PSWD_ENCODINGS parser reads password_obj[elem + pos_values] while copying the supported password encodings from the ACPI package.

The outer loop only guarantees that elem is within password_obj_count. The encoding count is bounded by MAX_ENCODINGS_SIZE, but that does not guarantee that the ACPI package contains enough entries for all elem + pos_values accesses.

A malformed package can therefore declare a non-zero encoding count without providing enough string objects, causing the parser to read past the ACPI package array and pass an out-of-bounds string pointer and length to hp_convert_hexstr_to_str().

Add the same computed-index bounds check used by the other offset-based package parsing loops before reading password_obj[elem + pos_values].