The vulnerable function d_expression_1 in cp-demangle.c was identified directly from the vulnerability description and confirmed by multiple security advisories (NVD, GitHub). Attempts to fetch detailed commit information from the provided bugzilla URLs failed due to anti-bot measures. However, the available information is highly consistent and explicitly names the function and the nature of the vulnerability (heap-based buffer over-read). Therefore, the identification is made with high confidence based on these textual descriptions rather than direct patch analysis, which was not possible in this instance. The function processes input in a way that can lead to reading beyond allocated buffer boundaries if the input is crafted maliciously, causing a denial of service (segmentation fault).