[wp-trac] [WordPress Trac] #36184: Eternal loop under certain conditions

[WordPress Trac]

#36184: Eternal loop under certain conditions
-------------------------+-----------------------------
 Reporter:  Mikk3lRo     |      Owner:
     Type:  enhancement  |     Status:  new
 Priority:  normal       |  Milestone:  Awaiting Review
Component:  General      |    Version:  4.4.2
 Severity:  normal       |   Keywords:
  Focuses:  performance  |
-------------------------+-----------------------------
 I've run into this quite a few times now, and often it puts a massive
 strain on the server and very rapidly fills the error log if logging is
 enabled.

 An very tight eternal loop in wp_mkdir_p() - wp-includes/functions.php
 line 1556 to 1613 - can be triggered if a path in the database is wrong.

 5 lines from line 1583 read:

 {{{#!php

 // We need to find the permissions of the parent folder that exists and
 inherit that.
 $target_parent = dirname( $target );
 while ( '.' != $target_parent && ! is_dir( $target_parent ) ) {
     $target_parent = dirname( $target_parent );
 }

 }}}



 I move wordpress installs around between servers and / or folders quite
 often, and sometimes an old (and now invalid) upload_path in the DB will
 cause this to loop forever. Obviously the mistake is mine for not
 correcting the path up front, but an eternal loop that may write to the
 error-log on each iteration (if open_basedir is active, possibly under
 other circumstances too) is not a very graceful way to fail... on a shared
 host (where you may not have the control I do) it could be pretty
 catastrophic.

 I'm not sure if other conditions are needed to trigger it, but I've only
 ever seen it when the upload path is wrong... seeing as it won't be
 triggered unless the path is wrong an easy solution would be to just check
 if '/' has been reached and throw an error pointing towards the
 solution...

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Ticket URL: <https://core.trac.wordpress.org/ticket/36184>
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