Language: C
Label: vulnerable
CWE: CWE-22 \u2014 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Code:
inline FIO_FUNC ssize_t fio_sendfile(intptr_t uuid, intptr_t source_fd,
                                     off_t offset, size_t length) {
  return fio_write2(uuid, .data.fd = source_fd, .length = length, .is_fd = 1,
                    .offset = offset);
}