[wp-trac] [WordPress Trac] #36936: Plugin update does not works via web with proper filesystem permissions.

[WordPress Trac]

#36936: Plugin update does not works via web with proper filesystem permissions.
----------------------------+-----------------------------
 Reporter:  brudas          |      Owner:
     Type:  defect (bug)    |     Status:  new
 Priority:  normal          |  Milestone:  Awaiting Review
Component:  Filesystem API  |    Version:  4.5.2
 Severity:  normal          |   Keywords:
  Focuses:                  |
----------------------------+-----------------------------
 Hello all,

 I run Wordpress 4.5.2 on Ext4 file system with POSIX ACL.
 Web server is Nginx, PHP runs as FPM daemon. Both under www-data user and
 group (for now).

 When I try to update some plugin, Wordpress ask me to enter FTP
 credentials instead of doing update.

 All output below was gathered under '''www-data''' account (PHP-FPM  runs
 under it).

 Here is my file system permissions:

 '''Document root:'''

 {{{
 $ getfacl /var/www/html/
 getfacl: Removing leading '/' from absolute path names
 # file: var/www/html/
 # owner: root
 # group: root
 user::rwx
 user:www-data:r-x
 group::---
 group:SA:rwx
 group:webdesigner:rwx
 mask::rwx
 other::---
 default:user::rwx
 default:user:www-data:r-x
 default:group::---
 default:group:SA:rwx
 default:group:webdesigner:rwx
 default:mask::rwx
 default:other::---
 }}}

 '''wp-content'''


 {{{
 $ getfacl /var/www/html/wp-content/
 getfacl: Removing leading '/' from absolute path names
 # file: var/www/html/wp-content/
 # owner: root
 # group: root
 user::rwx
 user:www-data:rwx
 group::---
 group:SA:rwx
 group:webdesigner:rwx
 mask::rwx
 other::---
 default:user::rwx
 default:user:www-data:rwx
 default:group::---
 default:group:SA:rwx
 default:group:webdesigner:rwx
 default:mask::rwx
 default:other::---
 }}}

 '''Plugins'''

 {{{
 $ getfacl /var/www/html/wp-content/plugins/
 getfacl: Removing leading '/' from absolute path names
 # file: var/www/html/wp-content/plugins/
 # owner: root
 # group: root
 user::rwx
 user:www-data:rwx
 group::---
 group:SA:rwx
 group:webdesigner:rwx
 mask::rwx
 other::---
 default:user::rwx
 default:user:www-data:rwx
 default:group::---
 default:group:SA:rwx
 default:group:webdesigner:rwx
 default:mask::rwx
 default:other::---

 }}}

 '''Plugin to be updated:'''


 {{{
 $ getfacl /var/www/html/wp-content/plugins/postmatic/
 getfacl: Removing leading '/' from absolute path names
 # file: var/www/html/wp-content/plugins/postmatic/
 # owner: root
 # group: root
 user::rwx
 user:www-data:rwx
 group::---
 group:SA:rwx
 group:webdesigner:rwx
 mask::rwx
 other::---
 default:user::rwx
 default:user:www-data:rwx
 default:group::---
 default:group:SA:rwx
 default:group:webdesigner:rwx
 default:mask::rwx
 default:other::---

 }}}

 Despite user www-data is explicitly granted to have write permissions to
 all required directories, Wordpress fails to start upgrade from web and
 asks for FTP credentials.

 I believe PHP works well enough with POSIX ACL, here is simply proof
 script:


 {{{
 $ php -r 'if (posix_access( "/var/www/html/wp-content/", POSIX_R_OK |
 POSIX_W_OK)) {
 echo "The file is readable and writable!\n";
 } else {
     $error = posix_get_last_error();

     echo "Error $error: " . posix_strerror($error);
 }'
 The file is readable and writable!

 }}}

 If there are some reason to keep current filesystem permission check
 method intact - please, issue spcecial technical note regarding required
 permissions and how does Wordpress checking it.

 System information:


 {{{
 $ lsb_release -a
 No LSB modules are available.
 Distributor ID: Ubuntu
 Description:    Ubuntu 14.04.4 LTS
 Release:        14.04
 Codename:       trusty

 $ php -v
 PHP 5.5.9-1ubuntu4.16 (cli) (built: Apr 20 2016 14:31:27)

 }}}

 There are no SuPHP, Suhosin or any suspicious extensions.

 This issue could be related to
 [https://core.trac.wordpress.org/ticket/34327]

 Thank you.

--
Ticket URL: <https://core.trac.wordpress.org/ticket/36936>
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