Same result on IBM AIX 5.2 ML8, although I'm using PHP 5.1.5 (no big difference) and have "php_admin_value upload_tmp_dir none" set (so it defaults to /tmp).

---8<---
Warning: move_uploaded_file(): open_basedir restriction in effect. File(/tmp/phpP5moMa) is not within the allowed path(s): (.:/apache/php/lib/php/:/apache/htdocs/bwiberg/) in /apache/htdocs/bwiberg/test/safemode/upload.php on line 9
--->8---

As you can see, /tmp is not within open_basedir, but I think it should not need to be...

---8<---
<?php
// In PHP versions earlier than 4.1.0, $HTTP_POST_FILES should be used instead
// of $_FILES.

$uploaddir = '/apache/htdocs/bwiberg/test/safemode/';
$uploadfile = $uploaddir . basename($_FILES['userfile']['name']);

echo '<pre>';
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)) {
   echo "File is valid, and was successfully uploaded.\n";
} else {
   echo "Possible file upload attack!\n";
}

echo 'Here is some more debugging info:';
print_r($_FILES);

print "</pre>";
?> 

--->8---

Best regards,
Bj?rn

Cannot reproduce with both 5.1.6 and latest CVS.
With upload_tmp_dir not set (aka "/tmp") and open_basedir="/www", I get this: File is valid, and was successfully uploaded.

Exact same behaviour with 4.4.4 under FreeBSD 6.1. 

Frustrating as this bug has appeared before.

Sorry, forgot to note that in our case, "upload_tmp_dir" is explicitly set.

Sorry for the flurry.  In our case it turned out that the error message was just misleading.  A simple permissions issue on the target directory was the cause (arrgh) but the error message explicitly stated that the problem was the open_basedir setting of the upload_tmp directory.  So more of an annoyance than a show stopper in our case.

Just tried it with PHP_5_2 (CVS), resulting in:
Warning: Unknown: open_basedir restriction in effect. 
File(/tmp) is not within the allowed path(s): (/var/www) 
in Unknown on line 0
 
 Warning: File upload error - unable to create a temporary 
file in Unknown on line 0


I've configured PHP just 
with "--with-apxs2=/usr/bin/apxs2" and use this simple 
php.ini file:
open_basedir = "/var"
display_errors=on
display_startup_errors=On
error_reporting=E_ALL

Reclassified as docu problem.
upload_tmp_dir must be in open_basedir() to be readable/writable.

Since when? As far as I understood, you have expected it 
to work like this (when trying to reproduce it).

Also, from older bug reports, it had been fixed to work 
like this again.

Additionally, from a security perspective, it would open 
up the upload_tmp_dir for all processes sharing the same 
php.ini/upload_tmp_dir and you would have to manually set 
it for every vhost where you use open_basedir for to an 
own directory.

If it's supposed to stay a documentation problem, please 
emphasize it in the NEWS/upgrade docs, because as it is 
now (e.g. failing since 5.1.6), it will break all upload 
scripts for hosts that use open_basedir.

IMHO it should work just like expected: PHP should 
internally allow the temporary uploaded file to get stored 
in upload_tmp_dir and should allow move_uploaded_file() to 
move it - PHP should know that it has to make an exception 
here to the regular open_basedir restriction (and it 
seemed to have done so before).

See this bug -  http://bugs.php.net/bug.php?id=37236
not any response from PHP :-)))

This bug has been fixed in the documentation's XML sources. Since the
online and downloadable versions of the documentation need some time
to get updated, we would like to ask you to be a bit patient.

Thank you for the report, and for helping us make our documentation better.

It seems to have been fixed in CVS for PHP_5_2 and HEAD 
(but not PHP_5_1).
Seems like iliaa has just used the wrong text snippet when 
closing the bug.

Thank you!