Fix OSS Fuzz #61865: Undef variable in ++/-- for declared property that is unset in error handler

Reorder when we assign the property value to NULL which is identical to
a3a3964

Just for the declared property case instead of dynamic.

Closes GH-12114

Author: Girgias

NEWS

@@ -10,6 +10,8 @@ PHP                                                                        NEWS
     closures). (ilutov)
   . Fixed bug GH-12060 (Internal iterator rewind handler is called twice).
     (ju1ius)
+  . Fixed OSS Fuzz #61865 (Undef variable in ++/-- for declared property
+    that is unset in error handler). (Girgias)
 
 
 - FPM:

Zend/tests/in-de-crement/oss-fuzz-61865_binop_declared_property_unset_error_handler.phpt

@@ -0,0 +1,18 @@
+--TEST--
+OSS Fuzz #61865: Undef variable in ++/-- for declared property that is unset in error handler
+--FILE--
+<?php
+class C {
+    public $a;
+    function errorHandler($errno, $errstr) {
+        unset($this->a);
+    }
+}
+$c = new C;
+set_error_handler([$c,'errorHandler']);
+unset($c->a);
+$c->a += 5;
+var_dump($c->a);
+?>
+--EXPECT--
+int(5)

Zend/tests/in-de-crement/oss-fuzz-61865_postdec_declared_property_unset_error_handler.phpt

@@ -0,0 +1,20 @@
+--TEST--
+OSS Fuzz #61865: Undef variable in ++/-- for declared property that is unset in error handler
+--FILE--
+<?php
+class C {
+    public $a;
+    function errorHandler($errno, $errstr) {
+        unset($this->a);
+    }
+}
+$c = new C;
+set_error_handler([$c,'errorHandler']);
+unset($c->a);
+$v = ($c->a--);
+var_dump($c->a);
+var_dump($v);
+?>
+--EXPECT--
+NULL
+NULL

Zend/tests/in-de-crement/oss-fuzz-61865_postinc_declared_property_unset_error_handler.phpt

@@ -0,0 +1,20 @@
+--TEST--
+OSS Fuzz #61865: Undef variable in ++/-- for declared property that is unset in error handler
+--FILE--
+<?php
+class C {
+    public $a;
+    function errorHandler($errno, $errstr) {
+        unset($this->a);
+    }
+}
+$c = new C;
+set_error_handler([$c,'errorHandler']);
+unset($c->a);
+$v = ($c->a++);
+var_dump($c->a);
+var_dump($v);
+?>
+--EXPECT--
+int(1)
+NULL

Zend/tests/in-de-crement/oss-fuzz-61865_predec_declared_property_unset_error_handler.phpt

@@ -0,0 +1,18 @@
+--TEST--
+OSS Fuzz #61865: Undef variable in ++/-- for declared property that is unset in error handler
+--FILE--
+<?php
+class C {
+    public $a;
+    function errorHandler($errno, $errstr) {
+        unset($this->a);
+    }
+}
+$c = new C;
+set_error_handler([$c,'errorHandler']);
+unset($c->a);
+(--$c->a);
+var_dump($c->a);
+?>
+--EXPECT--
+NULL

Zend/tests/in-de-crement/oss-fuzz-61865_preinc_declared_property_unset_error_handler.phpt

@@ -0,0 +1,18 @@
+--TEST--
+OSS Fuzz #61865: Undef variable in ++/-- for declared property that is unset in error handler
+--FILE--
+<?php
+class C {
+    public $a;
+    function errorHandler($errno, $errstr) {
+        unset($this->a);
+    }
+}
+$c = new C;
+set_error_handler([$c,'errorHandler']);
+unset($c->a);
+(++$c->a);
+var_dump($c->a);
+?>
+--EXPECT--
+int(1)

Zend/tests/in-de-crement/unset_property_converted_to_obj_in_error_handler.phpt

@@ -0,0 +1,25 @@
+--TEST--
+Unset declared property converted to object in error handler
+--FILE--
+<?php
+class C {
+    public $a;
+    function errorHandler() {
+        $this->a = new stdClass();
+    }
+}
+$c = new C;
+set_error_handler([$c,'errorHandler']);
+unset($c->a);
+
+try {
+    (++$c->a);
+} catch (\TypeError $e) {
+    echo $e->getMessage(), PHP_EOL;
+}
+var_dump($c->a);
+?>
+--EXPECT--
+Cannot increment stdClass
+object(stdClass)#2 (0) {
+}

Zend/zend_object_handlers.c

@@ -1117,8 +1117,11 @@ ZEND_API zval *zend_std_get_property_ptr_ptr(zend_object *zobj, zend_string *nam
 							ZSTR_VAL(name));
 						retval = &EG(error_zval);
 					} else {
-						ZVAL_NULL(retval);
 						zend_error(E_WARNING, "Undefined property: %s::$%s", ZSTR_VAL(zobj->ce->name), ZSTR_VAL(name));
+						/* An error handler may set the property */
+						 if (EXPECTED(Z_TYPE_P(retval) == IS_UNDEF)) {
+							ZVAL_NULL(retval);
+						 }
 					}
 				} else if (prop_info && UNEXPECTED(prop_info->flags & ZEND_ACC_READONLY)) {
 					/* Readonly property, delegate to read_property + write_property. */