Permissions of /var/run/mysqld too strict with Dapper

[Daniel Hahler]

The permissions on /var/run/mysqld directory are too strict, after dist-upgrading from breezy to dapper:

$ sudo ls -ld /var/run/mysqld
drwxrwx--- 2 mysql root 80 2006-01-10 18:11 /var/run/mysqld

This causes only the "mysql" user (and root) to be able to connect to MySQL through the socket in there
(/var/run/mysqld/mysqld.sock), causing the following error with a "normal" user (like the "Apache2 user"
also):

$ mysql -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (13)

I could not find a place where it might have happened. Perhaps it's even unrelated to the mysql-server
package.

I'd be interested in what caused this.

This fixed it:
$ sudo chmod a+x /var/run/mysqld

[Daniel Hahler (blueyed)]

The perms on /var/run/mysqld get reset here to rwxrwx--- here on every reboot, but I could not find anything
in /etc/init.d/ that would cause this..?!

[Jim Tarvid (tarvid)]

The original my.cnf includes the line

user = mysql

/usr/share/doc/mysql-server-5.0/examples/my-medium.cnf

does not.

Replacing my.cnf with my-medium.cnf permits mysqld to start.

Someone needs to arbitrate the security tradeoffs.

[Daniel Hahler (blueyed)]

Do you mean the "user=mysql"-line in /etc/mysql/my.cnf causes mysqld to chmod the /var/run/mysqld directory to 770?

[Daniel Hahler (blueyed)]

This seems to be related to the move of /var/run to tmpfs: http://lists.ubuntu.com/archives/ubuntu-devel-announce/2006-January/000048.html

Then, it has to be a wrong setting in the mysql-server part that creates this directory on startup.