MySQL Bugs: #97091: COM_RESET_CONNECTION does not respect CLIENT

Bug #97091	COM_RESET_CONNECTION does not respect CLIENT_INTERACTIVE
Submitted:	2 Oct 2019 20:56	Modified:	7 Nov 2019 1:47
Reporter:	Jason Rahman	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Security: Privileges	Severity:	S2 (Serious)
Version:	5.7+	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
If a connection is established with the CLIENT_INTERACTIVE flag set, COM_RESET_CONNECTION fails to set wait_timeout to interactive_timeout. This violates the expectation that CLIENT_INTERACTIVE instructs MySQL to set wait_timeout = interactive_timeout following COM_RESET_CONNECTION. Clients expecting the connection to be kept alive for interactive_timeout seconds instead experience errors rather than having a live and healthy connection to use following execution of COM_RESET_CONNECTION and then waiting less than interactive_timeout seconds.

How to repeat:
1. Open a connection to MySQL with the CLIENT_INTERACTIVE flag set
2. Execute 'SELECT @@session.wait_timeout;' to see that wait_timeout has been overridden with the value of interactive_timeout as expected
3. Execute COM_RESET_CONNECTION
4. Execute 'SELECT @@session.wait_timeout;' to see that wait_timeout is no longer reset to interactive_timeout as expected

Suggested fix:
Update the implementation of COM_RESET_CONNECTION to set wait_timeout = interactive_timeout if CLIENT_INTERACTIVE is set in the client capabilities negotiated on the original handshake.

Hi Mr. Rahman,

Thank you for your bug report.

I have analysed code which is described in your first comment and I conclude that you are correct.

Would it be difficult for you to share your patch with us ???? You can use "Files" tab to upload it.

Verified as reported.