Edit report at http://bugs.php.net/bug.php?id=52312&edit=1
ID: 52312
Comment by: v dot damore at gmail dot com
Reported by: v dot damore at gmail dot com
Summary: PHP safe_mode/open_basedir - lstat performance problem
Status: Analyzed
Type: Bug
Package: Safe Mode/open_basedir
Operating System: Linux
PHP Version: 5.2.13
New Comment:
Hello,
I have recompiled php commenting both in main/main.c:
/*
if (PG(safe_mode) || (PG(open_basedir) && *PG(open_basedir))) {
CWDG(realpath_cache_size_limit) = 0;
}
*/
I have defined into TSRM/tsrm_virtual_cwd.c
#define realpath(x,y) strcpy(y,x)
and I have disabled PHP function symlink.
Now I finally not have performance problems, but I suppose I still can
have
security problem.
Can you help me in order to understand if there is a better solution?
Previous Comments:
------------------------------------------------------------------------
[2010-07-14 16:25:28] v dot damore at gmail dot com
I want make it clear first that: in submitted test we can see only 4
directory scan, I my production environment I have seen up to 8
directory scan for php file.
If we disable PHAR I suppose only first full scan path will be removed.
So other 3 full scan path remain there, probably we need to change
php_check_specific_open_basedir in order to really try to remove
inefficiencies.
------------------------------------------------------------------------
[2010-07-14 15:58:22] [email protected]
Yup, there are clearly some inefficiencies here. We are relying too
much on the
realpath_cache being enabled. You can eliminate the phar one by
eliminating phar
for now. Recompile with --disable-phar until we get this cleaned up.
------------------------------------------------------------------------
[2010-07-14 15:43:52] v dot damore at gmail dot com
changed summery in order to provide a better description
------------------------------------------------------------------------
[2010-07-13 21:49:55] v dot damore at gmail dot com
Please pay attention correct URL for debugging info is
http://damore.xoom.it/apache-2.2_php-5.3.2_break-lstat.txt
------------------------------------------------------------------------
[2010-07-13 21:04:24] v dot damore at gmail dot com
If you take a look at debugging done in
http://damore.xoom.it/apache-2.2_php-5.3.2_break-lstat.txt, you can see
that tsrm_realpath_r is called in 2 different place:
- First during phar_find_in_include_path function
- Second during php_check_specific_open_basedir function.
* During php_check_specific_open_basedir, traverse entire path at least
three times, so i means 3 call to tsrm_realpath_r.
I don't discuss the need to traverse entire path, but only one time.
There should be a better way to implement such code, I'll try to write a
patch if there is someone that want help me looking what I'm writing.
------------------------------------------------------------------------
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