Bug #102205 ERROR 2027 (HY000): Malformed packet, from exception in nested procedures

Description:
1. A procedure has a exception handler that does a SELECT.
2. Its body calls a procedure that does a SELECT of a function
3. that function raises an exception. (by SIGNAL or actual exception).

mysql client returns ERROR 2027 (HY000): Malformed packet
and looses connection to server.

JDBC returns 
Exception: java.lang.StringIndexOutOfBoundsException
Message: offset 1, count 1, length 

removing the select in the exception handler causes mysql server to crash instead of ERROR 2027 (HY000): Malformed packet.

mysql> delimiter ^
mysql> create database if not exists bug^
Query OK, 1 row affected, 1 warning (0.00 sec)

mysql> drop procedure if exists bug.proc1^
Query OK, 0 rows affected (0.00 sec)

mysql> drop procedure if exists bug.proc2^
Query OK, 0 rows affected (0.00 sec)

mysql> drop function if exists bug.test^
Query OK, 0 rows affected (0.00 sec)

mysql> 
mysql> create procedure bug.proc1() 
    -> begin
    ->      declare exit handler for sqlexception
    ->           begin
    ->                select "in exception handler"; /*removing this causes mysql server to crash instead of ERROR 2027 (HY000): Malformed packet*/
    ->           end;   
    ->           call bug.proc2();
    -> end;
    -> ^
Query OK, 0 rows affected (0.00 sec)

mysql> create procedure bug.proc2() 
    -> begin
    ->      select bug.test(); /* doing the SIGNAL SQLSTATE '45000' here instead in the callee, removes ERROR 2027 (HY000): Malformed packet */
    -> end;
    -> ^
Query OK, 0 rows affected (0.00 sec)

mysql> create function bug.test() returns text 
    -> begin
    ->   SIGNAL SQLSTATE '45000'; /* or a real sql exception */
    ->   return "returned from bug.test function";
    -> end;
    -> ^
Query OK, 0 rows affected (0.00 sec)

mysql> call bug.proc1();
    -> ^
ERROR 2027 (HY000): Malformed packet
mysql> select version()^
ERROR 2013 (HY000): Lost connection to MySQL server during query
mysql> select version()^
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    51
Current database: *** NONE ***

+-----------+
| version() |
+-----------+
| 5.7.26    |
+-----------+
1 row in set (0.01 sec)

mysql> 

How to repeat:
delimiter ^
create database if not exists bug^
drop procedure if exists bug.proc1^
drop procedure if exists bug.proc2^
drop function if exists bug.test^

create procedure bug.proc1() 
begin
     declare exit handler for sqlexception
          begin
               select "in exception handler"; /*removing this causes mysql server to crash instead of ERROR 2027 (HY000): Malformed packet*/
          end;   
          call bug.proc2();
end;
^
create procedure bug.proc2() 
begin
     select bug.test(); /* doing the SIGNAL SQLSTATE '45000' here instead in the callee, removes ERROR 2027 (HY000): Malformed packet */
end;
^
create function bug.test() returns text 
begin
  SIGNAL SQLSTATE '45000';
  return "returned from bug.test function";
end;
^
call bug.proc1();
^

Suggested fix:
shouldn't do that!

The result of 
call bug.proc1();
should the result set from the select in the exception handler;

Thank you for the bug report. Verified as described with 8.0.22 too.

Reporter wrote "removing the select in the exception handler causes mysql server to crash instead of ERROR 2027 (HY000): Malformed packet."

Can you paste the mysql error log?  I didn't get a crash when removing this line,  only the connection hanged until I killed it.