MySQL Bugs: #109376: mysqlx_execute freeze on wrong input json format

Bug #109376	mysqlx_execute freeze on wrong input json format
Submitted:	14 Dec 2022 13:24	Modified:	16 Dec 2022 4:16
Reporter:	Ukrid Pawaktanon	Email Updates:
Status:	Analyzing	Impact on me:	None
Category:	Connector / C++	Severity:	S2 (Serious)
Version:	8.0.31	OS:	Ubuntu (22.04)
Assigned to:	MySQL Verification Team	CPU Architecture:	x86

Description:
My program will freeze if I run the wrong json path query on mysqlx_execute function 

I expected MySQL Connector C/C++ to return an error ,but it freezes

 mysqlx_result_t  *mysql_result = mysqlx_execute(crud_stmt);

Freeze !!! 
Select JSON_EXTRACT(json_body,'invoice_date') FROM invoice_db 
Select json_body->>'$.index_-1' FROM invoice_db 

OK 
Select JSON_EXTRACT(json_body,'$.invoice_date') FROM invoice_db 
Select json_body->>'$.index_0' FROM invoice_db 

How to repeat:

Freeze !!! 
Select JSON_EXTRACT(json_body,'invoice_date') FROM invoice_db 
Select json_body->>'$.index_-1' FROM invoice_db 

OK 
Select JSON_EXTRACT(json_body,'$.invoice_date') FROM invoice_db 
Select json_body->>'$.index_0' FROM invoice_db

Hi Mr. Pawaktanon,

Thank you for your bug report.

However, we need also the table involved in this query and it's contents.

It seems that a negative offset in json_body->>'$.index_ triggers a problem, but we have to be able to reproduce it.

//table
CREATE TABLE `invoice_db` (
  `id` int NOT NULL,
  `json_body` json NOT NULL,
  `status` tinyint NOT NULL DEFAULT '1'
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3;

//json_body
{"state": "normal","invoice_date": "2022-12-13"}

mysqlx_stmt_t *crud_stmt = mysqlx_sql_new(mysql_session,"Select JSON_EXTRACT(json_body,'invoice_date') FROM invoice_db",MYSQLX_NULL_TERMINATED); // create stmt

if ( crud_stmt ) {

	//freeze here 
	mysqlx_result_t  *mysql_result = mysqlx_execute(crud_stmt);

}

Hi Mr. Pawaktanon,

Thank you for providing some of the test case.

However, we need full test case.

We need contents of the data and the entire source  program that you use and that will lead to the error.

Can you try executing the same commands from MySQL CLI or MySQL Shell ?????

Waiting on your feedback.

Hi MySQL Verification Team,

Thank you for your prompt reply. Sorry for my bad English. 

Yes I already tried the same sql query on MySQL-Shell ,it worked properly

With my invalid JSON path query I got 

ERROR 3143 (42000): Invalid JSON path expression. The error is around character position 1.

I expected the same thing on mysqlx_execute function ,but it freezed

,I writed this code on C++ Thread ,when it got freezed ,it never leave from the Thread.

mysqlx_error_t *error_get_session=nullptr;

mysqlx_client_t *mysql_session = mysqlx_get_client_from_url(
                         GetMySqlClientConStringUrl(m_db_con_param_struct) 
                        , "{\"pooling\": {\"enabled\": true,\"maxSize\": 100,\"queueTimeout\": 5000,\"maxIdleTime\": 5000}}"
                        , &error_get_session
                       );
                       
if ( error_get_session ) {

	std::string error_msg=std::string{ mysqlx_error_message(error_get_session) };
            
	mysqlx_free(error_get_session);
		
	return error_msg;
}
        
        
if ( mysql_session ) {
        
    //try invalid json-path with invoice_date ,the correct is $.invoice_date    
    const std::string prepare_sql_str="Select JSON_EXTRACT(json_body,'invoice_date')"; 

    mysqlx_stmt_t *mysql_crud_stmt = mysqlx_sql_new(mysql_session, e_prepare_sql_str.c_str() ,MYSQLX_NULL_TERMINATED); // create stmt

    if ( mysql_crud_stmt ) {

       //***freeze here 
       mysqlx_result_t  *mysql_result = mysqlx_execute(mysql_crud_stmt);
    }

}