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Bug #53489 Passthru and Signals Appear Not Handled
Submitted: 2010-12-06 23:08 UTC Modified: 2021-04-25 04:22 UTC
Votes:1
Avg. Score:3.0 ± 0.0
Reproduced:0 of 1 (0.0%)
From: broberts at ieee dot org Assigned: cmb (profile)
Status: No Feedback Package: Unknown/Other Function
PHP Version: 5.3.3 OS: Centos5
Private report: No CVE-ID: None
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 [2010-12-06 23:08 UTC] broberts at ieee dot org
Description:
------------
So I'm not really sure if this is a configuration issue or a bug, but passthru doesn't seem to be handling the signal due to ulimit as expected on Centos5.  

If I run myscript.sh at the bash command line, I get a nice "File too large detected via return code" show up and 2.1 MB of the 5 MB file copied. So it appears cp child process caught and handled the SIGXFSZ signal.

But when I run the PHP script, while the o/s stops cp at 2.1 MB, but ${LOCALRET} is 1 (of course I also see the "Got 0 as always" message as myscript.sh always returns 0). Somehow the child of myscript.sh isn't getting the signal properly it seems. In fact if it's a more elaborate process than a cp, it will not stop the process -- The process appears not to have gotten the signal (of course the o/s won't let it write more than 2.1 MB but it seems to be obvious to the signal).

When I'm on MacOS (running same PHP 5.3.3 with Apache 2) the signals seem to work correctly. So am I misunderstanding something here? Is there a configuration setting in PHP to make the Centos behave like the MacOS?  Or is this a Centos PHP bug?

BTW the Centos configure options are:
./configure --with-mysqli --with-zlib --with-xml --with-mysql --with-openssl --enable-sockets --enable-calendar --with-curl --with-apxs2

Test script:
---------------
<?php 
echo "<pre>";
passthru('/bin/myscript.sh',$return_code);
echo "<br>";
echo "Got $return_code as always";
echo "</pre>";
?>



#!/bin/bash

# set max write size to 2.1 MB and trigger SIGXFSZ
ulimit -f 2100  

cp /path/5mb_file /path/5mb_file.cp
LOCALRET=$?

# return code = 128+SIGXFSZ = 153 (on Centos and MacOS anyway)
if [[ ${LOCALRET} -eq 153 ]]; then
 echo "File too large detected via return code"
else
 echo "Got ${LOCALRET}"
fi

exit 0

Expected result:
----------------
File too large detected via return code
Got 0 as always

Actual result:
--------------
Got 1
Got 0 as always

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 [2020-10-11 13:09 UTC] divinity76 at gmail dot com
are you using a 100 year old version of PHP? 5.3.3? that one is no longer supported (maybe Red Hat still support 5.3.3, in which case go complain to Red Hat's bugtracker, not PHP's bugtracker)

see if the problem reproduce itself in a supported version of PHP, 7.2 or 7.3 or 7.4


for what it's worth, here's what i get: 

hans@xDevAd:~$ cat foo.php
<?php 
$filepath="/tmp/test_script_file.sh";
$fileh=fopen($filepath,"wb");
$code='
#!/bin/sh
cd /tmp
ulimit -f 2100
dd if=/dev/zero of=5mb_test_file.bin bs=5M count=1
';
fwrite($fileh,$code);
chmod($filepath,0555);
fclose($fileh);
passthru($filepath,$ret);
var_dump($ret,filesize("/tmp/5mb_test_file.bin"));
unlink("/tmp/5mb_test_file.bin");
unlink("/tmp/test_script_file.sh");

hans@xDevAd:~$ php foo.php
File size limit exceeded (core dumped)
int(153)
int(1075200)


- as expected.
 [2021-04-13 12:00 UTC] cmb@php.net
-Status: Open +Status: Feedback -Assigned To: +Assigned To: cmb
 [2021-04-13 12:00 UTC] cmb@php.net
> are you using a 100 year old version of PHP? 5.3.3?

Well, that tickets has been filed more than ten years ago.

Anyhow, is this still an issue with any of the actively supported
PHP versions[1]?

[1] <https://www.php.net/supported-versions.php>
 [2021-04-25 04:22 UTC] php-bugs at lists dot php dot net
No feedback was provided. The bug is being suspended because
we assume that you are no longer experiencing the problem.
If this is not the case and you are able to provide the
information that was requested earlier, please do so and
change the status of the bug back to "Re-Opened". Thank you.
 
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