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I'd like to for once leave SELinux running on a server for the alleged increased security.
I usually disable SELinux to get anything to work.
How do I tell SELinux to allow MySQL connections?
The most I've found in the documentation is this line from mysql.com:

If you are running under Linux and Security-Enhanced Linux (SELinux) is enabled, make sure you have disabled SELinux protection for the mysqld process.

wow ... that's really helpful.

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    Please provide all of the following information for us to have a chance of helping you. 1. Linux Distro and Version, 2. MySQL version and installation source, 3. AVC log entries from a denied connection, 4. Relevant MySQL logs, if any 5. The output of getsebool -a | grep mysql 6. Exact steps you have taken to reproduce this
    – hobodave
    Feb 24, 2011 at 23:25

6 Answers 6

58

To check SELinux

sestatus

To see what flags are set on httpd processes

getsebool -a | grep httpd

To allow Apache to connect to remote database through SELinux

setsebool httpd_can_network_connect_db 1

Use -P option makes the change permanent. Without this option, the boolean would be reset to 0 at reboot.

setsebool -P httpd_can_network_connect_db 1
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    seems to be necessary when connecting via 127.0.0.1 loopback as well? Jun 29, 2015 at 18:19
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    @Devin, definitely.
    – e18r
    Aug 4, 2016 at 0:32
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    If you want to allow users to connect to the local mysql server, you must turn on the selinuxuser_mysql_connect_enabled boolean also. May 18, 2017 at 11:47
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    setsebool -P httpd_can_network_connect 1 may also be needed. This was suggested in my logs by running ausearch -m avc -ts today | audit2why as suggested in a comment by vnix27.
    – site
    Jun 12, 2019 at 17:38
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Do you get an error? What flavor of linux are you using? Security context is a good place to start if you are getting an error. ls -Z will give context... But your question is very vague.

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  • I am connecting from a windows box. There is no error ... the connection is just refused and the page times out. I know if I turn off selinux everything will be fine.
    – xivix
    Feb 24, 2011 at 21:17
  • since the connection is incoming from a windows box, ls -Z only gives me info about the files in whatever directory I'm in on the linux box.
    – xivix
    Feb 24, 2011 at 21:18
  • In my question above I cited a mysql reference ... which said to disable selinux protection for the mysqld process ... but it doesn't say how to do that :( Nor can I find out how.
    – xivix
    Feb 24, 2011 at 21:20
  • Anything in the logs on the linux box? selinux can stop httpd from making a socket connection...
    – Tamler
    Feb 24, 2011 at 21:35
  • Nothing in messages or secure logs ... is there a particular log you had in mind?
    – xivix
    Feb 24, 2011 at 21:46
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Apparently configuring selinux isn't trivial. You may wish to start here.

setenforce 0

puts selinux into permissive mode, where it allows anything but logs what it's allowing. A reboot or

setenforce 1

returns to blocking whatever the policy doesn't permit.

Check out these selinux policy docs for mySQL in Fedora.

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you can build local policy too:

"You can generate a local policy module to allow this access.Do allow this access for now by executing:"

grep httpd /var/log/audit/audit.log | audit2allow -M mypol

semodule -i mypol.pp

or enable globally for the actual session:

setsebool httpd_can_network_connect_db 1

or permanent:

setsebool -P httpd_can_network_connect_db 1
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Are you sure it's selinux? Normal connections from outside should be allowed by selinux. So it could also be the firewall. If you have local services trying to connect to mysqld, that's something different: http://docs.fedoraproject.org/en-US/Fedora/13/html/Managing_Confined_Services/sect-Managing_Confined_Services-MySQL-Booleans.html

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The ausearch command can help find the error log.

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    ausearch -m avc -ts today | audit2why , command can suggest solution
    – vnix27
    Feb 26, 2011 at 7:01

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