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Fix open_basedir leak #11780

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Fix open_basedir leak #11780

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9 changes: 9 additions & 0 deletions Zend/tests/oss_fuzz_60741.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,9 @@
--TEST--
oss-fuzz #60741: Leak in open_basedir when using non-constant string
--INI--
open_basedir="{TMP}"
--FILE--
<?php
ini_set('open_basedir', ini_get('open_basedir'));
?>
--EXPECT--
18 changes: 0 additions & 18 deletions Zend/zend.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1271,29 +1271,11 @@ void zend_call_destructors(void) /* {{{ */
}
/* }}} */

static void zend_release_open_basedir(void)
{
/* Release custom open_basedir config, this needs to happen before ini shutdown */
if (PG(open_basedir)) {
zend_ini_entry *ini_entry = zend_hash_str_find_ptr(EG(ini_directives), "open_basedir", strlen("open_basedir"));
/* ini_entry->modified is unreliable, it might also be set when on_update has failed. */
if (ini_entry
&& ini_entry->modified
&& ini_entry->value != ini_entry->orig_value) {
efree(PG(open_basedir));
PG(open_basedir) = NULL;
}
}
}

ZEND_API void zend_deactivate(void) /* {{{ */
{
/* we're no longer executing anything */
EG(current_execute_data) = NULL;

/* Needs to run before zend_ini_deactivate(). */
zend_release_open_basedir();

zend_try {
shutdown_scanner();
} zend_end_try();
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18 changes: 10 additions & 8 deletions main/fopen_wrappers.c
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Expand Up @@ -77,8 +77,12 @@ PHPAPI ZEND_INI_MH(OnUpdateBaseDir)
char *pathbuf, *ptr, *end;

if (stage == PHP_INI_STAGE_STARTUP || stage == PHP_INI_STAGE_SHUTDOWN || stage == PHP_INI_STAGE_ACTIVATE || stage == PHP_INI_STAGE_DEACTIVATE) {
if (PG(open_basedir_modified)) {
efree(*p);
}
/* We're in a PHP_INI_SYSTEM context, no restrictions */
*p = new_value ? ZSTR_VAL(new_value) : NULL;
PG(open_basedir_modified) = false;
return SUCCESS;
}

Expand Down Expand Up @@ -117,15 +121,13 @@ PHPAPI ZEND_INI_MH(OnUpdateBaseDir)
efree(pathbuf);

/* Everything checks out, set it */
if (*p) {
/* Unfortunately entry->modified has already been set to true so we compare entry->value
* against entry->orig_value. */
if (entry->modified && entry->value != entry->orig_value) {
efree(*p);
}
}
zend_string *tmp = smart_str_extract(&buf);
*p = estrdup(ZSTR_VAL(tmp));
char *result = estrdup(ZSTR_VAL(tmp));
if (PG(open_basedir_modified)) {
efree(*p);
}
*p = result;
PG(open_basedir_modified) = true;
zend_string_release(tmp);

return SUCCESS;
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1 change: 1 addition & 0 deletions main/php_globals.h
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Expand Up @@ -80,6 +80,7 @@ struct _php_core_globals {
char *user_dir;
char *include_path;
char *open_basedir;
bool open_basedir_modified;
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I know @nielsdos did some struct packing at one time, but there was also one case where it wasn't super worth it to do it compared to keeping the relevant bits nearby. Might have been the globals struct

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Yeah. I prefer keeping related globals together, as it's easier to understand but also potentially improves cache locality. I'm not going to die on a hill for this though.

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I indeed did a bit of struct packing here too. When I did it I made sure that fields that were in the same cacheline were still in the same line after reordering. However, packing is not important here, this is fine as-is imo.

char *extension_dir;
char *php_binary;
char *sys_temp_dir;
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