Fix bug #75306: Memleak in SoapClient

Setting the stream context via php_stream_context_to_zval() will
increase the reference count. So if the new context is created, then it
will end up with a reference count of 2 while it should be 1.

Credits to cmb for the analysis. I arrived at the same patch as he did.

Closes GH-12523.

Author: nielsdos

NEWS

@@ -36,6 +36,7 @@ PHP                                                                        NEWS
   . Fix segfault and assertion failure with refcounted props and arrays.
     (nielsdos)
   . Fix potential crash with an edge case of persistent encoders. (nielsdos)
+  . Fixed bug #75306 (Memleak in SoapClient). (nielsdos)
 
 - Streams:
   . Fixed bug #75708 (getimagesize with "&$imageinfo" fails on StreamWrappers).

ext/soap/php_sdl.c

@@ -3255,6 +3255,9 @@ sdlPtr get_sdl(zval *this_ptr, char *uri, zend_long cache_wsdl)
 		tmp = Z_CLIENT_STREAM_CONTEXT_P(this_ptr);
 		if (Z_TYPE_P(tmp) == IS_RESOURCE) {
 			context = php_stream_context_from_zval(tmp, 0);
+			/* Share a reference with new_context down below.
+			 * For new contexts, the reference is only in new_context so that doesn't need extra refcounting. */
+			GC_ADDREF(context->res);
 		}
 
 		tmp = Z_CLIENT_USER_AGENT_P(this_ptr);
@@ -3323,7 +3326,7 @@ sdlPtr get_sdl(zval *this_ptr, char *uri, zend_long cache_wsdl)
 	}
 
 	if (context) {
-		php_stream_context_to_zval(context, &new_context);
+		ZVAL_RES(&new_context, context->res);
 		php_libxml_switch_context(&new_context, &orig_context);
 	}
 

ext/soap/tests/bug75306.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Bug #75306 (Memleak in SoapClient)
+--EXTENSIONS--
+soap
+--FILE--
+<?php
+$options = array("cache_wsdl" => WSDL_CACHE_NONE);
+// Need a warm-up for globals
+for ($i = 0; $i < 10; $i++) {
+    $client = new SoapClient("ext/soap/tests/test.wsdl", $options);
+}
+$usage = memory_get_usage();
+for ($i = 0; $i < 10; $i++) {
+    $client = new SoapClient("ext/soap/tests/test.wsdl", $options);
+}
+$usage_delta = memory_get_usage() - $usage;
+var_dump($usage_delta);
+?>
+--EXPECT--
+int(0)