php.net |  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login

go to bug id or search bugs for

Doc Bug #73114 php segfault probably because OpenBSD wx implementation
Submitted: 2016-09-19 15:09 UTC Modified: 2016-11-13 14:39 UTC
Votes:2
Avg. Score:3.5 ± 1.5
Reproduced:1 of 1 (100.0%)
Same Version:1 (100.0%)
Same OS:1 (100.0%)
From: martin dot larsson2 at gmail dot com Assigned: cmb (profile)
Status: Closed Package: PCRE related
PHP Version: 7.0.11 OS: OpenBSD
Private report: No CVE-ID: None
View Developer Edit
Welcome back! If you're the original bug submitter, here's where you can edit the bug or add additional notes.
If you forgot your password, you can retrieve your password here.
Password:
Status:
Package:
Bug Type:
Summary:
From: martin dot larsson2 at gmail dot com
New email:
PHP Version: OS:

 

 [2016-09-19 15:09 UTC] martin dot larsson2 at gmail dot com 
Description:
------------
# php-7.0 broke.php                                                                                                                                        
Abort trap (core dumped) 
# 

php segfault probably becouse of OpenBSD wx implementation, must stuff seem to work but preg_replace segfaults php.                                                                                                                                         


Test script:
---------------
<?php
$string = 'April 15, 2003';
$pattern = '/(\w+) (\d+), (\d+)/i';
$replacement = '${1}1,$3';
echo preg_replace($pattern, $replacement, $string);
?>

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2016-09-19 15:38 UTC] cmb@php.net
-Status: Open +Status: Feedback -Package: Reproducible crash +Package: PCRE related -Assigned To: +Assigned To: cmb
 [2016-09-19 15:38 UTC] cmb@php.net 
What's your setting of pcre.jit? If it's 1, please set to 0 and
try again.

Also it would be helpful to know which version of libpcre you're
using.
 [2016-09-19 17:03 UTC] martin dot larsson2 at gmail dot com
-Status: Feedback +Status: Assigned
 [2016-09-19 17:03 UTC] martin dot larsson2 at gmail dot com 
pcre-8.38p0 is the version installed.

and yes it works if I use pcre.jit=0
 [2016-09-19 17:49 UTC] cmb@php.net 
Thanks. I'll have a closer look at the issue.
 [2016-09-19 17:56 UTC] martin dot larsson2 at gmail dot com 
I just checked dmesg, and it says
php-7.0(10468): mmap W^X violation

just to be clear :)
 [2016-11-09 15:10 UTC] ab@php.net
-Status: Assigned +Status: Feedback
 [2016-11-09 15:10 UTC] ab@php.net 
@martin dot larsson2 at gmail dot com, could you check bug #72281 please? Seems it's same issue.

thanks.
 [2016-11-09 20:00 UTC] martin dot larsson2 at gmail dot com
-Status: Feedback +Status: Assigned
 [2016-11-09 20:00 UTC] martin dot larsson2 at gmail dot com 
ehm, I don't know sorry. Thought https://bugs.php.net/bug.php?id=72281 was a compilation error?
 [2016-11-09 20:13 UTC] cmb@php.net 
> Thought https://bugs.php.net/bug.php?id=72281 was a compilation error?

No. Actually it appears to be the very same issue:

 * this ticket: mmap W^X violation
 * the other ticket: it does not allow mapping pages both writable and
   executable

Martin, could you please check whether the patch attached to the other
ticket would solve the issue for you?
 [2016-11-11 14:05 UTC] martin dot larsson2 at gmail dot com 
php doesnt compile for me at all, I use the package.

I get wx violation just trying to compile it, and that netbsd patch use some paxctl which openbsd doesnt have.
 [2016-11-11 16:40 UTC] cmb@php.net 
Ah, I see, thanks! Please try to build with:

  CFLAGS="-fpie -pie" ./configure …

Cf. <https://www.openbsd.org/papers/asiabsdcon2015-pie-slides.pdf>.
 [2016-11-11 17:39 UTC] martin dot larsson2 at gmail dot com 
same error with CFLAGS="-fpie -pie" ./configure

here is paste http://pastebin.ca/3738078
 [2016-11-11 18:11 UTC] cmb@php.net
-Summary: php segfault probably becouse OpenBSD wx implementation +Summary: php segfault probably because OpenBSD wx implementation
 [2016-11-11 18:11 UTC] cmb@php.net 
Thanks! I've found an article[1] which includes the commit message
regarding the W^X violation protection. It seems to me that for now you
have to use the "wxallowed" mount option. Alternatively, building PHP
without PCRE JIT support (--without-pcre-jit) should also work (assuming
that this is indeed the only part that uses W|X mmap).

[1] <http://undeadly.org/cgi?action=article&sid=20160527203200>
 [2016-11-11 18:20 UTC] martin dot larsson2 at gmail dot com 
yes it works without that, but that we knew from the beginning right?:)

anyways if you want login to my openbsd vm feel free to mail
 [2016-11-11 18:46 UTC] cmb@php.net 
> anyways if you want login to my openbsd vm feel free to mail

Thanks for the offer, but that wouldn't help, unfortunately. I've just
found a closely related bug report on the PCRE bug tracker[1] which
makes it clear that the issue would have to be resolved there. However,
that appears to be non-trivial, if possible at all. :-(

I've just emailed the internals mailing list[2] – maybe somebody else
has a solution.

[1] <https://bugs.exim.org/show_bug.cgi?id=1749>
[2] <http://news.php.net/php.internals/96837>
 [2016-11-13 14:35 UTC] cmb@php.net 
Automatic comment from SVN on behalf of cmb
Revision: http://svn.php.net/viewvc/?view=revision&amp;revision=340988
Log: Document W^X/PaX MPROTECT issues

Fix #72281: PaX MPROTECT breaks php
Fix #73114: php segfault probably because OpenBSD wx implementation
 [2016-11-13 14:38 UTC] cmb@php.net
-Status: Assigned +Status: Closed
 [2016-11-13 14:38 UTC] cmb@php.net 
We have decided that this is not an issue that PHP should try to
solve, but rather to document the problem and possible solutions.
 [2016-11-13 14:39 UTC] cmb@php.net
-Type: Bug +Type: Documentation Problem
 
PHP Copyright © 2001-2024 The PHP Group
All rights reserved. 		Last updated: Tue Nov 26 22:01:33 2024 UTC