Linux

CentOS 7 + SELinux + PHP + Apache – cannot write/access file no matter what

  • July 8, 2015

I’ve spent 2-3 hours pulling my hair trying to setup a supposed to be simple PHP/MySQL web application on an Amazon EC2 instance running on CentOS 7. Apache logs keep saying that it can’t write to file due to permission where file permissions are properly setup, only to realize it was SELinux in action.

Problem 1: Can’t serve files on a custom directory

The first problem I have encountered is that I tried to setup the application inside /data/www/html/sites/mysite. When viewed on the browser, it says 403 Forbidden and error logs says:

13)Permission denied: [client 121.54.44.93:23180] AH00529: /data/www/html/sites/mysite/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable and that '/data/www/html/sites/mysite/' is executable

The directory structure has proper ownership and permissions, ex: directory is owned by apache:apache, file permission is 0644 and directory permission is 0755. It doesn’t make sense at all. I noticed though that the default document root has no problem serving the php file so I decided to serve it off the /var/www/html/mysite directory, which is the default document root.

Problem 2: Can’t write to file

Moving to the default document root directory did the trick and I was able to run the application but with errors. The error says it can’t write to file although again, proper permissions are already set to the directory. Below is the error (it is a custom error log, but if writing to log file doesn’t work, imagine how your upload functionality would work):

PHP Warning:  fopen(/var/www/html/mysite/application/config/../../logs/web/20150708.ALL.log): failed to open stream: Permission denied in /var/www/html/mysite/application/core/App_Exceptions.php

Surprise! SELinux is here!

You guys choose CentOS, so you got SELinux as well.

After realizing that it was SELinux whose messing with me for the past 2 hours, I was thinking of ditching CentOS and go with the recommended Ubuntu instead. But then my instinct tells me that if SELinux is blocking the read/write operations, it must did it for a good reason, and that was for security. I realize that you need to specify which files/directories Apache can serve files and which files/directories it can write into.

SELinux seems to have some rules/policies that applies to files/directories on top of the unix file permissions structure. When I run the command below on the default document root, I saw more information on the file/directory permissions.

ls -Z /var/www/html/mysite

Below is the output (some information removed):

drwxr-xr-x. apache apache unconfined_u:object_r:httpd_sys_content_t:s0 application
-rw-r--r--. apache apache unconfined_u:object_r:httpd_sys_content_t:s0 index.php

And below is what I got for other normal directories:

drwxr-xr-x. apache apache unconfined_u:object_r:default_t:s0 www

Therefore, we can conclude that we need to specify the proper SELinux permissions on directories in order to serve files on a custom directory and set another SELinux permissions to allow writing to file. Therefore, we can solve the original problem then.

Fixing the original problem

So we want to serve our files at /data/www/html/sites/mysite and enable writing to log files and file uploads as well? Let’s play nice with SELinux.

First, copy the files as usual to /data/www/html/sites/mysite, then set the proper ownership and permissions.

# Ownership
sudo chown apache:apache -R /data/www/html/sites/mysite
cd /data/www/html/sites/mysite

# File permissions, recursive
find . -type f -exec chmod 0644 {} \;

# Dir permissions, recursive
find . -type d -exec chmod 0755 {} \;

# SELinux serve files off Apache, resursive
sudo chcon -t httpd_sys_content_t /data/www/html/sites/mysite -R

# Allow write only to specific dirs
sudo chcon -t httpd_sys_rw_content_t /data/www/html/sites/mysite/logs -R
sudo chcon -t httpd_sys_rw_content_t /data/www/html/sites/mysite/uploads -R

httpd_sys_content_t – for allowing Apache to serve these contents and httpd_sys_rw_content_t – for allowing Apache to write to those path.

That’s it! I enjoyed and you share!

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95 Comments

95 thoughts on “CentOS 7 + SELinux + PHP + Apache – cannot write/access file no matter what”

  2. Perfect, I solved my “zend forbidden permission” issue with your help,
    # SELinux serve files off Apache, resursive
    sudo chcon -t httpd_sys_content_t /data/www/html/sites/mysite -R
    Thank you so much!

  4. This is what saved me, was struggling for about 6hrs yesterday and today combined to attempt to fix it and I was nowhere close. This knocked out my problem first try.
    Thanks for taking the time to make this guide!

    Bookmarked!

  6. httpd_sys_rw_content_t will be replaced back after restorecon
    for example: restorecon -R “/data/www/html/sites/mysite”
    better use
    semanage fcontext -a -t httpd_sys_rw_content_t “/data/www/html/sites/mysite/uploads(/.*)?”
    to apply the settings permanently

  11. Thanks for the post. The problem with selinux problems is that you have to know have to know that its an selinux problem before you google. Otherwise, you just end up with people saying you’ve just chown’d or chmod’d wrong. *sigh*

    Your site popped right up and solved my problem once I knew the problem. Thanks again!

  12. THANK GOD,
    THANKS FOR THIS LINE:
    sudo chcon -t httpd_sys_rw_content_t /data/www/html/sites/mysite/logs -R
    THANK YOUUUUUU, centos is so painful for the permissions ^^

  13. I’m glad that it helps! We are trying to switch to Ubuntu Wily by the way, which is a new beast to me.

  14. Hi,

    Just to leave an opinion.
    I don’t like nor recommend Ubuntu for production servers (and it’s widely discouraged).
    CentOS/RedHat and it’s relatives are rock solid server material.

    Regarding this issue and SELinux, by setting the content type to httpd_sys_content_t you don’t need to chown the files to apache user/group.

  15. We’re ditching CentOS completely as we can’t really catch up with more recent PHP packages with CentOS 7. Not sure what happens during the EOL of PHP 5.4 but right now, we are even planning to get PHP 7 with Ubuntu Xenial.

  16. Hi,
    Thank you for sharing the solution to this problem!
    It really saved my day.
    I was having trouble having WordPress writing its configuration file during install.
    While searching CentOS and WordPress related issues, all I found on the internet was recommendations of changing ownership and rights, which were already set correctly.
    I had no knowledge of the SELinux imposed security mechanism.

  19. Hi,
    You are a life time saver !
    I spend about 2 days on it, desable SELinux is not a issu, they made it for a purpose I believed !

    I have a website by default with ‘root’ as the owner and it goes nicely. But when I decide to add another one I have got that f**king error, I even change the owner to the ‘root’ same thing.
    I am not a Linux Admin, but I used to host some website on Centos.

    Again thanks !

  20. thank you, works on centos 7 + php + wordpress->(migration).

    again, thank you.

  25. THANKS for the accurate, simple notes.

    For CentOS 7 + SELinux + Apache + SVN, I used all your fix steps through SELinux serve files off Apache, resursive, but then, instead of adjusting logs and uploads, I gave httpd_sys_rw_content_t on the ./db and ./locks subdirectories under each repo. That solved my problem of trying to commit changes to the repository.

    Sample error message had been:
    Commit failed (details follow):
    Can’t move
    ‘/var/www/(snip)/db/txn-protorevs/3992-32y.rev’
    to ‘/var/www/(snip)/db/revs/3/3993’:
    Permission denied

  26. @chloe, that’s odd. If you just do the svn or git stuff as a regular user or a user with enough permissions, you should be able to perform svn/git commands without messing up with SELinux.

  27. I have had this issue for the past two days! I’ve had the hosting support on the case changing folder permissions, apache configuration, php configuration with no luck.

    I am so grateful, thank you so much!

  28. Pingback: Sometimes it is annoying – Paolo Redaelli

  31. Wow
    6 hours of search online on why third party install was not able to write to the installation folder (nothing generic to search for) and then I run into your post, run the commands you provided and bam!!!. it worked like a charm

    Thank you, thank you, thousand thank you’s!!!!!
    you’ve made my day!!

  32. Thanks a lot.
    chcon -t httpd_sys_rw_content_t symfony/app/cache -R
    chcon -t httpd_sys_rw_content_t symfony/app/logs -R
    It works.

  33. Thank you! This solved my ResourceSpace installation issue, I sent a link to this page for them to review in their docs, hope that is okay.

  36. You saved me! I have been scratching my head for 3 hours now.
    Never heard of this before.
    Thanks a lot Lysender.
    Thank you for sharing <3

  37. So what happens when SELinux is disabled?
    SELinux is disabled on my CentOS7 install and I still cannot write to folders outside of my web root.

  40. Agreed! SELinux should be enabled and specify the right security setting rather than disabling it completely.

  42. It doesn’t work for me. If SELinux disabled OK, but with SELinux even with your sulution doesn’t work.

  47. Incredible, this should be everywhere! fixed my problems with mpdf. Holy smokes I spent all weekend trying to get this to work. Thanks!!

  48. WOW this has been so helpful eish I was about to dish CentOS 7 to Fedora or even go back to ubuntu. Finally this has been my rescue. Thumbs up….

  50. Thanks a lot. I’ve been retooling from Ubuntu to CentOS. On the one hand SELinux is “annoying” and “in the way” and on the other hand, it seems a platform with a reason to exist. Thanks for the help!

  54. Awesome … It Worked..I was just going to switch back to debian… thinking of some problem in cent os 7… but its security… Thank You..

  56. This Article just save me from my poor Linux knowlegde, I just install apache 2.4 on my centos 7 lab virtual machine and i was has the same problem for the past fews days now.
    Thanks for this nice article

  58. Thank you very much !
    You helped me so much to resolve my issue.
    I took a lot of time but cannot resolve it.
    Thanks for great article!

  59. This is an amazing post, you know, you have saved many hard working people!! You are super hero!!!!!!

    Thank you very much!!

  63. Could not get my Drupal 8 site to work properly until I found your post. You saved my day, sir 🙂

  65. It is worth to share on Social Sites, however, I don’t see any option for Social Sharing.

    Please advise.

  66. @Palbinder, I removed the Facebook/Google share buttons to remove those trackers. If you use desktop, you can just copy and paste the URL. On mobile, well, not sure.

  67. Thanks for your useful information. I just thought I would share some since I am also using Centos (7) for server with Apache. I did some tests and found that PHP/Apache PHP can operate with all directories as permissions “100” and can write to a log file that is permissions “200”. So, in a production server, the following permissions are just fine (working on localhost at least).

    # File permissions, recursive
    find . -type f -exec chmod 0400 {} \;

    # Dir permissions, recursive
    find . -type d -exec chmod 0100 {} \;

  68. November 2018 and there you are, you saved my day. More hours spend and gray hairs grown, kept getting a PHP permission denied at mkdir, hours of ownerships and groups changing, reading and what not, thank you sir!
    SELinux!!! thank you for this article!

  69. @Lucian – I’m glad it helps. It’s been a long time since I’ve used CentOS as I’m mostly using Ubuntu or Alpine.

  75. Thanks a lot for this post, had this issue since Monday. Worked great for CENTOS 7. This post was from 3 + yrs ago. Good job

  76. Thank you lysender! I was struck for 24 hours to fix this File Open Permission issue on Google Cloud Compute Engine but could not.

    Your post solved it like a charm!

    Great JOB! Thank you once again!

  77. Hi, I have this error but in the same server exist a web site, the question is: have I need to do other modifications?
    Thank you.

  78. @seafree – I don’t know what your question exactly is, so I don’t have an answer 😀

  80. httpd_sys_rw_content_t
    Perfect! That’s what I was looking for (apache httpd file write permission).
    Thanks

  84. Spent a good couple of hours before this post. Thank you so much for this. Works on CentOs 7

    P.S. I hate CentOs

  87. Spent a week before this post … why didn’t this come up sooner in the list of answers????

    Thank you, Lysender!

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