MySQL Bugs: #93276: Crash when calling mysql_real

Bug #93276	Crash when calling mysql_real_connect() in loop
Submitted:	21 Nov 2018 13:55	Modified:	17 Dec 2018 19:27
Reporter:	Reggie Burnett	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: C API (client library)	Severity:	S2 (Serious)
Version:	8.0.13	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
Hi! See the attached test program. It calls in loop following sequence:

mysql_library_init(), mysql_init(), mysql_real_connect(), mysql_close(), mysql_library_end()

It is working fine for MySQL versions below 8.0.4. Since 8.0.4 it
crashes at second loop iteration in function mysql_real_connect().

I guess that problem is somewhere in mysql_library_end() or in
mysql_library_init() which free or initialize some global structures.

As there is no crash in version 8.0.3 and below, that problem must have
been introduced in MySQL version 8.0.4 and is present also in 8.0.11,
8.0.12 and 8.0.13 version.

I do not know if you are correct person for contacting about this issue.
If not can you resend this problem to relevant MySQL team?

I discovered this problem while developing and testing Perl DBI
connector DBD::MariaDB for accessing MariaDB and MySQL databases.

How to repeat:
Run the attached program.

test file

Attachment: test-init.c (application/octet-stream, text), 993 bytes.

Hello Reggie,

Thank you for the report and feedback.

regards,
Umesh

Posted by developer:
 
Fixed in 8.0.15.

Opening and closing a connection multiple times in a client program
could cause the client to exit due to improper character set
reinitialization.

Posted by developer:
 
Fixed in 8.0.20.

Reinitialization of character sets from Index.xml could cause a
use-after-free error.