The vulnerability is a buffer overflow due to an excessive allocation size. The issue #427 on GitHub, referenced in the vulnerability details, points to this problem. The commit 221e767136b8c46c748ae35b79ec9b976b3da301 fixes this issue by adding checks for the validity of conformance window parameters within the de265_image::alloc_image function. This function is responsible for image allocation and is where the excessive allocation could occur if the parameters are not validated. The ASAN log in the issue also points to convert_to_8bit and display_sdl in dec265.cc, but the core issue fixed in the commit is in alloc_image. The other functions are higher in the call stack and are affected by the incorrect allocation size originating from alloc_image or a similar allocation function if not alloc_image itself. However, the provided patch directly modifies alloc_image to prevent the oversized allocation, making it the most directly identifiable vulnerable function based on the patch. The other functions mentioned in the ASAN log (operator new[], convert_to_8bit, display_sdl, output_image, main) are part of the call chain leading to or utilizing the oversized allocation, but the root cause addressed by the patch is within alloc_image's logic for determining allocation size based on input parameters (conformance window).