#47520 [Bgs]: PHP segfaulted in preg_replace on processing long string

ID: 47520 User updated by: pahan at hubbitus dot spb dot su Reported By: pahan at hubbitus dot spb dot su Status: Bogus Bug Type: PCRE related Operating System: Linux PHP Version: 5.3.0beta1 New Comment: Problem in pcre library is a problem of pcre library. BUT segmentation fault of PHP is a bug PHP itself in any case!!! I can understand what it may be very hard to fix, but completely do not understand why you mark it as Bogus! Previous Comments: ------------------------------------------------------------------------ [2009-03-03 01:40:03] iliaa@php.net There is not much we can do about recursion limits other then suggest the lowering of the pcre.recursion_limit setting. The basic problem is that PCRE library (not PHP) is eating up the system stack during recursion and subsequently crashes when it runs out of room. This is not a PHP bug. ------------------------------------------------------------------------ [2009-03-02 10:09:28] phpwnd at gmail dot com I forgot to add that in my case, lowering the value the pcre.recursion_limit INI setting make preg_* functions fail instead of making PHP segfault. ------------------------------------------------------------------------ [2009-03-02 10:01:52] phpwnd at gmail dot com I'd like to add that you don't need such a complicated test case, you can make preg_* segfault with just something like: $str = str_repeat(' ', 2490); preg_match('#(.)+#', $str); On my computer, a 2490-chars string is long enough to make it segfaults everytime. For some reason, 2489 chars will make it segfault only 1 out of 5 runs and 2480 chars are perfectly fine. If I replace the regexp with more capturing parenthesis such as #((.))+# that limit drops to 1500-or-so and that number decreases as the number of parenthesis increases. Using non-capturing patterns such as #(?:.)+# doubles that number. Obviously, the bug is related to capturing patterns repetition, assuming we're experiencing the same bug. I'll try to find a place where to host a core dump. ------------------------------------------------------------------------ [2009-02-28 09:00:02] pahan at hubbitus dot spb dot su Very apologize for mistake. I'm fix rights now, please recheck. ------------------------------------------------------------------------ [2009-02-28 01:19:21] felipe@php.net I cannot download the coredump file: "You don't have permission to access /_temp/php-pcre-bug/2/core.10135 on this server." Can you give us a backtrace? ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/47520 -- Edit this bug report at http://bugs.php.net/?id=47520&edit=1