MySQL Bugs: #72760: SERVER NOT ACCEPTING SOME CONNECTIONS WHEN OFFLINE

Bug #72760	SERVER NOT ACCEPTING SOME CONNECTIONS WHEN OFFLINE_MODE IS ON
Submitted:	27 May 2014 6:40	Modified:	27 Mar 2015 2:46
Reporter:	Atanu Ghosh	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Security: Privileges	Severity:	S3 (Non-critical)
Version:	5.7.5	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
The server runs into a race condition and occasionally rejects
SUPER connections when OFFLINE_MODE is TRUE.

The different error message seen are:

1) \

How to repeat:
Run following from two terminals
 
cat f.sh
for i in {1..4096}
do
   echo \

Suggested fix:
Root user must be allowed to connect.

Posted by developer:
 
Description:

The server runs into a race condition and occasionally rejects
SUPER connections when OFFLINE_MODE is TRUE.

The different error message seen are:

1) ERROR 2013 (HY000): Lost connection to MySQL server at
'reading authorization packet', system error: 95

2) ERROR 2013 (HY000): Lost connection to MySQL server at
'sending authentication information', system error: 32

3) ERROR 2006 (HY000) at line 1: MySQL server has gone away

How to repeat:

Run following from two terminals
 
cat f.sh
for i in {1..4096}
do
   echo "Welcome $i times"
   ./mysql -uroot -e "SET @@global.offline_mode = TRUE;SET
@@global.offline_mode = FALSE;"
done

Noted in 5.7.7, 5.8.0 changelogs.

With the offline_mode system variable enabled, the server sometimes
failed to accept connection from a user with the SUPER privilege due
to a race condition.