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

go to bug id or search bugs for

Bug #61744 preg_match crashes
Submitted: 2012-04-16 10:57 UTC Modified: 2012-04-17 09:37 UTC
From: bugzilla33 at gmail dot com Assigned:
Status: Not a bug Package: *Regular Expressions
PHP Version: 5.4.1RC2 OS: Win 7 64-bit
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: bugzilla33 at gmail dot com
New email:
PHP Version: OS:

 

 [2012-04-16 10:57 UTC] bugzilla33 at gmail dot com 
Description:
------------
preg_match crashes

Test script:
---------------
<?=preg_match('#^(A{1,2}B)+$#',str_repeat('AB',300));?>

Expected result:
----------------
preg_match no crash

Actual result:
--------------
preg_match crashes

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2012-04-16 11:01 UTC] bugzilla33 at gmail dot com 
Try as Apache module.
php.exe testcase.php does not crash
 [2012-04-16 14:52 UTC] laruence@php.net 
Thank you for this bug report. To properly diagnose the problem, we
need a backtrace to see what is happening behind the scenes. To
find out how to generate a backtrace, please read
http://bugs.php.net/bugs-generating-backtrace.php for *NIX and
http://bugs.php.net/bugs-generating-backtrace-win32.php for Win32

Once you have generated a backtrace, please submit it to this bug
report and change the status back to "Open". Thank you for helping
us make PHP better.

I think it is probable because of : 
http://www.php.net/manual/en/pcre.configuration.php#ini.pcre.recursion-limit
 [2012-04-16 14:52 UTC] laruence@php.net
-Status: Open +Status: Feedback
 [2012-04-16 16:13 UTC] bugzilla33 at gmail dot com 
I checked recursion-limit:
pcre.backtrack_limit 1000000
pcre.recursion_limit 100000

On fastCGI or direct php.exe testcase.php does not crash.

When use Apache 2.2.21 with php module with the same php.ini
testcase.php crash apache.

Now I am at home. The same crash like at work - two other machines.
 [2012-04-16 16:13 UTC] bugzilla33 at gmail dot com
-Status: Feedback +Status: Open
 [2012-04-16 16:18 UTC] rasmus@php.net 
Windows-only, I assume? Apache uses PCRE as well, so perhaps Apache on Windows is 
resetting the PCRE limits? I assume it doesn't crash if you reduce the 300 there 
to something smaller?
 [2012-04-16 16:29 UTC] bugzilla33 at gmail dot com 
str_repeat('AB',200) do not crash

str_repeat('AB',300) crashes - browser freeze about 4sec and info - browser can not display site
 [2012-04-16 16:31 UTC] bugzilla33 at gmail dot com 
...but using apache module phpinfo also says:
pcre.backtrack_limit 1000000
pcre.recursion_limit 100000
 [2012-04-16 16:34 UTC] bugzilla33 at gmail dot com 
...and I tested Windows 7 only (32-bit and 64-bit)
 [2012-04-16 16:37 UTC] bugzilla33 at gmail dot com 
When use #^(A{1}B)+$# instead of #^(A{1,2}B)+$#
testcase returns 1 - no crash
 [2012-04-16 16:53 UTC] bugzilla33 at gmail dot com 
Tested also on Apache 2.4.2 + php_module (from www.apachelounge.com) + PHP 5.4.0 VC9 Thread Safe

Test script still crashes.
 [2012-04-16 17:12 UTC] rasmus@php.net 
Are you using mod_security in your Apache?
 [2012-04-16 17:23 UTC] bugzilla33 at gmail dot com 
No, I have original httpd.conf from package
and original php.ini-development -> php.ini
 [2012-04-16 17:36 UTC] pajoye@php.net
-Status: Open +Status: Not a bug
 [2012-04-16 17:36 UTC] pajoye@php.net 
Increase the stack, either using the http configuration or using the editbin.exe 
utility.

The stack is overridden by the executable running php, in case of mod_php it is 
apache's.
 [2012-04-16 20:20 UTC] bugzilla33 at gmail dot com 
I think that this is not the fault of the stack.
In PHP 5.3 this problem does not occur.
 [2012-04-17 08:58 UTC] pajoye@php.net 
Different pcre version or code, the situation where a crash occurs may differ. 
However all the symptoms of a stack related crash are present. Increase it and you 
should be good.
 [2012-04-17 09:37 UTC] bugzilla33 at gmail dot com 
I increased by editbin to 8mb and it works!

Why apache is compiling with 256kb stack?
Is stack increasing dangerous?
 
PHP Copyright © 2001-2024 The PHP Group
All rights reserved. 		Last updated: Sat Dec 21 17:01:58 2024 UTC