Skip to content

Fix use-after-free in XPath php:function argument nodes #22468

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
iliaal wants to merge 1 commit into from
+45 −4
Closed

Fix use-after-free in XPath php:function argument nodes #22468

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
33 changes: 33 additions & 0 deletions ext/dom/tests/xpath_php_function_removes_argument_node.phpt
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,33 @@
--TEST--
DOMXPath: a php:function callback that removes its argument node must not free it mid-evaluation
--EXTENSIONS--
dom
--FILE--
<?php
$doc = new DOMDocument();
$doc->loadXML('<root><a>1</a><a>2</a><a>3</a><a>4</a></root>');
$xp = new DOMXPath($doc);
$xp->registerNamespace('php', 'http://php.net/xpath');
$xp->registerPhpFunctions();

function cb($nodes) {
foreach ($nodes as $n) {
if ($n->parentNode) {
$n->parentNode->removeChild($n);
}
}
return true;
}

$res = $xp->query('//a[php:function("cb", .)]');
foreach ($res as $r) {
var_dump($r->nodeName);
}
echo "done\n";
?>
--EXPECT--
string(1) "a"
string(1) "a"
string(1) "a"
string(1) "a"
done
16 changes: 12 additions & 4 deletions ext/dom/xpath_callbacks.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -381,11 +381,19 @@ static zval *php_dom_xpath_callback_fetch_args(xmlXPathParserContextPtr ctxt, ui
return params;
}

static void php_dom_xpath_callback_cleanup_args(zval *params, uint32_t param_count)
static void php_dom_xpath_callback_cleanup_args(php_dom_xpath_callbacks *xpath_callbacks, zval *params, uint32_t param_count)
{
if (params) {
for (uint32_t i = 0; i < param_count; i++) {
zval_ptr_dtor(&params[i]);
zval *param = &params[i];
if (Z_TYPE_P(param) == IS_OBJECT || Z_TYPE_P(param) == IS_ARRAY) {
if (xpath_callbacks->node_list == NULL) {
xpath_callbacks->node_list = zend_new_array(0);
}
zend_hash_next_index_insert_new(xpath_callbacks->node_list, param);
} else {
zval_ptr_dtor(param);
}
}
efree(params);
}
Expand Down Expand Up @@ -483,7 +491,7 @@ PHP_DOM_EXPORT zend_result php_dom_xpath_callbacks_call_php_ns(php_dom_xpath_cal

cleanup:
xmlXPathFreeObject(obj);
php_dom_xpath_callback_cleanup_args(params, param_count);
php_dom_xpath_callback_cleanup_args(xpath_callbacks, params, param_count);
cleanup_no_obj:
if (UNEXPECTED(result != SUCCESS)) {
/* Push sentinel value */
Expand Down Expand Up @@ -511,7 +519,7 @@ PHP_DOM_EXPORT zend_result php_dom_xpath_callbacks_call_custom_ns(php_dom_xpath_

zend_result result = php_dom_xpath_callback_dispatch(xpath_callbacks, ns, ctxt, params, param_count, function_name, function_name_length);

php_dom_xpath_callback_cleanup_args(params, param_count);
php_dom_xpath_callback_cleanup_args(xpath_callbacks, params, param_count);
if (UNEXPECTED(result != SUCCESS)) {
/* Push sentinel value */
valuePush(ctxt, xmlXPathNewString((const xmlChar *) ""));
Expand Down
Loading