static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
{
	const char *p = *ident;
	char *end;

	*ident = strchrnul(*ident, '\n');
	if (**ident == '\n')
		(*ident)++;

	if (*p == '<')
		return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
	p += strcspn(p, "<>\n");
	if (*p == '>')
		return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
	if (*p != '<')
		return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
	if (p[-1] != ' ')
		return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
	p++;
	p += strcspn(p, "<>\n");
	if (*p != '>')
		return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
	p++;
	if (*p != ' ')
		return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
	p++;
	if (*p == '0' && p[1] != ' ')
		return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
	if (date_overflows(parse_timestamp(p, &end, 10)))
		return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
	if ((end == p || *end != ' '))
		return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
	p = end + 1;
	if ((*p != '+' && *p != '-') ||
	    !isdigit(p[1]) ||
	    !isdigit(p[2]) ||
	    !isdigit(p[3]) ||
	    !isdigit(p[4]) ||
	    (p[5] != '\n'))
		return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
	p += 6;
	return 0;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.