#45735 [Bgs]: preg_match fails with Segmentation Fault on capturing subpattern

ID: 45735 Updated by: lbarnaud@php.net Reported By: johnston dot joshua at gmail dot com Status: Bogus Bug Type: PCRE related Operating System: * PHP Version: 5.2CVS, 5.3CVS, 6CVS (2008-08-06) New Comment: I seen that PCRE has a NO_RECURSE flag to avoid the recursion in match() (described in pcre_exec.c). Defining NO_RECURSE at compile time avoids this problem :) diff -u -r1.38.2.3.2.10.2.3 config0.m4 --- ext/pcre/config0.m4 2 Jun 2008 14:12:20 -0000 1.38.2.3.2.10.2.3 +++ ext/pcre/config0.m4 7 Aug 2008 11:25:39 -0000 @@ -59,7 +59,7 @@ pcrelib/pcre_ord2utf8.c pcrelib/pcre_refcount.c pcrelib/pcre_study.c \ pcrelib/pcre_tables.c pcrelib/pcre_try_flipped.c pcrelib/pcre_valid_utf8.c \ pcrelib/pcre_version.c pcrelib/pcre_xclass.c" - PHP_NEW_EXTENSION(pcre, $pcrelib_sources php_pcre.c, no,,- + PHP_NEW_EXTENSION(pcre, $pcrelib_sources php_pcre.c, no,,- PHP_ADD_BUILD_DIR($ext_builddir/pcrelib) PHP_INSTALL_HEADERS([ext/pcre], [php_pcre.h pcrelib/]) AC_DEFINE(HAVE_BUNDLED_PCRE, 1, [ ]) Previous Comments: ------------------------------------------------------------------------ [2008-08-07 08:28:20] derick@php.net AFAIK only be using a non-stack based evaluator (pcre_dfa_exec)... which is not compatible with the perl regular expressions, see the description at http://manpages.courier-mta.org/htmlman3/pcre_dfa_exec.3.html ------------------------------------------------------------------------ [2008-08-06 17:47:50] johnston dot joshua at gmail dot com I understand it is a known pcre behavior but does that mean it is ok to let pcre trigger a segmentation fault? Is there no possible way to handle this failure gracefully? ------------------------------------------------------------------------ [2008-08-06 17:40:50] felipe@php.net . ------------------------------------------------------------------------ [2008-08-06 17:40:08] felipe@php.net That is known PCRE behavior. See: http://manpages.courier-mta.org/htmlman3/pcrestack.3.html ------------------------------------------------------------------------ [2008-08-06 17:29:06] johnston dot joshua at gmail dot com In my case the parens were unnecessary so I removed them which stopped the Seg Fault. Is there a way to handle this error from inside php? If I set pcre.backtrack_limit to any other value will it always seg fault if it is too low? ------------------------------------------------------------------------ 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/45735 -- Edit this bug report at http://bugs.php.net/?id=45735&edit=1