static void tsc210x_write(TSC210xState *s, uint16_t value)
{
    /*
     * This is a two-state state machine for reading
     * command and data every second time.
     */
    if (!s->state) {
        s->command = value >> 15;
        s->page = (value >> 11) & 0x0f;
        s->offset = (value >> 5) & 0x3f;
        s->state = 1;
    } else {
        if (s->command)
            fprintf(stderr, "tsc210x_write: SPI overrun!\n");
        else
            switch (s->page) {
            case TSC_DATA_REGISTERS_PAGE:
                tsc2102_data_register_write(s, s->offset, value);
                break;
            case TSC_CONTROL_REGISTERS_PAGE:
                tsc2102_control_register_write(s, s->offset, value);
                break;
            case TSC_AUDIO_REGISTERS_PAGE:
                tsc2102_audio_register_write(s, s->offset, value);
                break;
            default:
                hw_error("tsc210x_write: wrong memory page\n");
            }

        tsc210x_pin_update(s);
        s->state = 0;
    }
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.