update integer overflow

src/Others/3.3.2_integer.c

@@ -0,0 +1,20 @@
+#include<stdio.h>
+#include<string.h>
+void validate_passwd(char *passwd) {
+	char passwd_buf[11];
+	unsigned char passwd_len = strlen(passwd);
+	if(passwd_len >= 4 && passwd_len <= 8) {
+		printf("good!\n");
+		strcpy(passwd_buf, passwd);
+	} else {
+		printf("bad!\n");
+	}
+}
+
+int main(int argc, char *argv[]) {
+	if(argc != 2) {
+		printf("error\n");
+		return 0;
+	}
+	validate_passwd(argv[1]);
+}