Merge branch 'PHP-8.4' into PHP-8.5

* PHP-8.4:
  ext/xsl: XSLTProcessor::importStylesheet() use-after-free during a transformation.

Author: devnexen

ext/xsl/php_xsl.h

@@ -55,6 +55,7 @@ extern zend_module_entry xsl_module_entry;
 typedef struct xsl_object {
 	void *ptr;
 	HashTable *parameter;
+	uint32_t transform_depth;
 	bool hasKeys;
 	php_libxml_ref_obj *sheet_ref_obj;
 	zend_long securityPrefs;

ext/xsl/tests/gh23730.phpt

@@ -0,0 +1,81 @@
+--TEST--
+GH-23730 (Use-after-free when a stylesheet is imported during a transformation)
+--EXTENSIONS--
+dom
+xsl
+--CREDITS--
+djarfluka
+--FILE--
+<?php
+
+class MyElement extends DOMElement {
+    public function __destruct() {
+        /* Runs while the node list of the finished transformation is torn down. */
+        import_other('destructor');
+    }
+}
+
+function import_other(string $from) {
+    try {
+        $GLOBALS['proc']->importStylesheet($GLOBALS['other']);
+        echo $from, ': no error', PHP_EOL;
+    } catch (Error $e) {
+        echo $from, ': ', $e::class, ': ', $e->getMessage(), PHP_EOL;
+    }
+}
+
+function callback($nodes) {
+    import_other('callback');
+    return $nodes[0];
+}
+
+$xml = new DOMDocument();
+$xml->registerNodeClass(DOMElement::class, MyElement::class);
+$xml->loadXML('<root><item>a</item></root>');
+
+$xsl = new DOMDocument();
+$xsl->loadXML(<<<XML
+<?xml version="1.0"?>
+<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:php="http://php.net/xsl">
+  <xsl:template match="/"><xsl:value-of select="php:function('callback', //item)"/></xsl:template>
+</xsl:stylesheet>
+XML);
+
+$other = new DOMDocument();
+$other->loadXML('<?xml version="1.0"?><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"><xsl:template match="/">REPLACED</xsl:template></xsl:stylesheet>');
+
+$proc = new XSLTProcessor();
+$proc->registerPHPFunctions();
+$proc->importStylesheet($xsl);
+
+$GLOBALS['proc'] = $proc;
+$GLOBALS['other'] = $other;
+
+var_dump($proc->transformToXml($xml));
+var_dump($proc->transformToDoc($xml)->textContent);
+
+$uri = tempnam(sys_get_temp_dir(), 'gh23730');
+var_dump($proc->transformToUri($xml, $uri) > 0);
+@unlink($uri);
+
+/* Importing outside of a transformation is still allowed. */
+var_dump($proc->importStylesheet($other));
+var_dump($proc->transformToXml($xml));
+
+?>
+--EXPECT--
+callback: Error: Cannot call XSLTProcessor::importStylesheet() while a transformation is in progress
+destructor: Error: Cannot call XSLTProcessor::importStylesheet() while a transformation is in progress
+string(24) "<?xml version="1.0"?>
+a
+"
+callback: Error: Cannot call XSLTProcessor::importStylesheet() while a transformation is in progress
+destructor: Error: Cannot call XSLTProcessor::importStylesheet() while a transformation is in progress
+string(1) "a"
+callback: Error: Cannot call XSLTProcessor::importStylesheet() while a transformation is in progress
+destructor: Error: Cannot call XSLTProcessor::importStylesheet() while a transformation is in progress
+bool(true)
+bool(true)
+string(31) "<?xml version="1.0"?>
+REPLACED
+"

ext/xsl/xsltprocessor.c

@@ -175,6 +175,12 @@ PHP_METHOD(XSLTProcessor, importStylesheet)
 		RETURN_THROWS();
 	}
 
+	xsl_object *intern = Z_XSL_P(id);
+	if (UNEXPECTED(intern->transform_depth > 0)) {
+		zend_throw_error(NULL, "Cannot call XSLTProcessor::importStylesheet() while a transformation is in progress");
+		RETURN_THROWS();
+	}
+
 	nodep = php_libxml_import_node(docp);
 	if (nodep == NULL) {
 		zend_argument_type_error(1, "must be a valid XML node");
@@ -251,8 +257,6 @@ PHP_METHOD(XSLTProcessor, importStylesheet)
 		RETURN_FALSE;
 	}
 
-	xsl_object *intern = Z_XSL_P(id);
-
 	/* Detach object */
 	clone_lxml_obj->document->ptr = NULL;
 	/* The namespace mappings need to be kept alive.
@@ -333,6 +337,8 @@ static xmlDocPtr php_xsl_apply_stylesheet(zval *id, xsl_object *intern, xsltStyl
 		return NULL;
 	}
 
+	intern->transform_depth++;
+
 	if (intern->profiling) {
 		if (php_check_open_basedir(ZSTR_VAL(intern->profiling))) {
 			f = NULL;
@@ -438,6 +444,8 @@ static xmlDocPtr php_xsl_apply_stylesheet(zval *id, xsl_object *intern, xsltStyl
 	efree(intern->doc);
 	intern->doc = NULL;
 
+	intern->transform_depth--;
+
 	return newdocp;
 
 }