fix some heap buffer overflows

Author: Qwinci

src/basic/main.c

@@ -292,12 +292,12 @@ void library_statement(struct basic_ctx* ctx)
 
 	/* Load the library file from VFS */
 	size_t library_len = file_info->size;
-	char* temp_library = kmalloc(library_len);
+	char* temp_library = kmalloc(library_len + 1);
 	if (!temp_library) {
 		tokenizer_error_print(ctx, "Not enough memory to load library file");
 		return;
 	}
-	char* clean_library = kmalloc(library_len);
+	char* clean_library = kmalloc(library_len + 1);
 	if (!clean_library) {
 		kfree_null(&temp_library);
 		tokenizer_error_print(ctx, "Not enough memory to load library file");

src/string.c

@@ -234,9 +234,9 @@ char* strdup(const char* string)
 	if (!string) {
 		return NULL;
 	}
-	uint32_t len = strlen(string) + 1;
-	char* result = kmalloc(len);
-	strlcpy(result, string, len);
+	uint32_t len = strlen(string);
+	char* result = kmalloc(len + 1);
+	strlcpy(result, string, len + 1);
 	*(result + len) = 0;
 	return result;
 }
@@ -246,9 +246,9 @@ char* gc_strdup(const char* string)
 	if (!string) {
 		return NULL;
 	}
-	uint32_t len = strlen(string) + 1;
-	char* result = kmalloc(len);
-	strlcpy(result, string, len);
+	uint32_t len = strlen(string);
+	char* result = kmalloc(len + 1);
+	strlcpy(result, string, len + 1);
 	*(result + len) = 0;
 
 	if (gc_list == NULL) {