Allow FETCH_OBJ_W and FETCH_STATIC_PROP_W to return INDIRECT/UNDEF zval for uninitialized typed properties (#11048)

Author: dstogov

Zend/Optimizer/zend_inference.c

@@ -3436,6 +3436,9 @@ static zend_always_inline int _zend_update_type_info(
 					tmp |= zend_fetch_prop_type(script, prop_info, &ce);
 					if (opline->result_type == IS_VAR) {
 						tmp |= MAY_BE_REF | MAY_BE_INDIRECT;
+						if ((opline->extended_value & ZEND_FETCH_OBJ_FLAGS) == ZEND_FETCH_DIM_WRITE) {
+							tmp |= MAY_BE_UNDEF;
+						}
 					} else if (!(opline->op1_type & (IS_VAR|IS_TMP_VAR)) || !(t1 & MAY_BE_RC1)) {
 						zend_class_entry *ce = NULL;
 
@@ -3473,6 +3476,9 @@ static zend_always_inline int _zend_update_type_info(
 				zend_fetch_static_prop_info(script, op_array, ssa, opline), &ce);
 			if (opline->result_type == IS_VAR) {
 				tmp |= MAY_BE_REF | MAY_BE_INDIRECT;
+				if ((opline->extended_value & ZEND_FETCH_OBJ_FLAGS) == ZEND_FETCH_DIM_WRITE) {
+					tmp |= MAY_BE_UNDEF;
+				}
 			} else {
 				if (!result_may_be_separated(ssa, ssa_op)) {
 					tmp &= ~MAY_BE_RC1;

Zend/zend_execute.c

@@ -3087,7 +3087,7 @@ static zend_never_inline bool zend_handle_fetch_obj_flags(
 	return 1;
 }
 
-static zend_always_inline void zend_fetch_property_address(zval *result, zval *container, uint32_t container_op_type, zval *prop_ptr, uint32_t prop_op_type, void **cache_slot, int type, uint32_t flags, bool init_undef OPLINE_DC EXECUTE_DATA_DC)
+static zend_always_inline void zend_fetch_property_address(zval *result, zval *container, uint32_t container_op_type, zval *prop_ptr, uint32_t prop_op_type, void **cache_slot, int type, uint32_t flags OPLINE_DC EXECUTE_DATA_DC)
 {
 	zval *ptr;
 	zend_object *zobj;
@@ -3203,9 +3203,6 @@ static zend_always_inline void zend_fetch_property_address(zval *result, zval *c
 			}
 		}
 	}
-	if (init_undef && UNEXPECTED(Z_TYPE_P(ptr) == IS_UNDEF)) {
-		ZVAL_NULL(ptr);
-	}
 
 end:
 	if (prop_op_type != IS_CONST) {
@@ -3219,7 +3216,7 @@ static zend_always_inline void zend_assign_to_property_reference(zval *container
 	void **cache_addr = (prop_op_type == IS_CONST) ? CACHE_ADDR(opline->extended_value & ~ZEND_RETURNS_FUNCTION) : NULL;
 
 	zend_fetch_property_address(variable_ptr, container, container_op_type, prop_ptr, prop_op_type,
-		cache_addr, BP_VAR_W, 0, 0 OPLINE_CC EXECUTE_DATA_CC);
+		cache_addr, BP_VAR_W, 0 OPLINE_CC EXECUTE_DATA_CC);
 
 	if (EXPECTED(Z_TYPE_P(variable_ptr) == IS_INDIRECT)) {
 		variable_ptr = Z_INDIRECT_P(variable_ptr);

Zend/zend_object_handlers.c

@@ -1037,6 +1037,8 @@ ZEND_API zval *zend_std_get_property_ptr_ptr(zend_object *zobj, zend_string *nam
 				} else if (prop_info && UNEXPECTED(prop_info->flags & ZEND_ACC_READONLY)) {
 					/* Readonly property, delegate to read_property + write_property. */
 					retval = NULL;
+				} else if (!prop_info || !ZEND_TYPE_IS_SET(prop_info->type)) {
+					ZVAL_NULL(retval);
 				}
 			} else {
 				/* we do have getter - fail and let it try again with usual get/set */

Zend/zend_vm_def.h

@@ -2157,7 +2157,7 @@ ZEND_VM_HANDLER(85, ZEND_FETCH_OBJ_W, VAR|UNUSED|THIS|CV, CONST|TMPVAR|CV, FETCH
 	zend_fetch_property_address(
 		result, container, OP1_TYPE, property, OP2_TYPE,
 		((OP2_TYPE == IS_CONST) ? CACHE_ADDR(opline->extended_value & ~ZEND_FETCH_OBJ_FLAGS) : NULL),
-		BP_VAR_W, opline->extended_value & ZEND_FETCH_OBJ_FLAGS, 1 OPLINE_CC EXECUTE_DATA_CC);
+		BP_VAR_W, opline->extended_value & ZEND_FETCH_OBJ_FLAGS OPLINE_CC EXECUTE_DATA_CC);
 	FREE_OP2();
 	if (OP1_TYPE == IS_VAR) {
 		FREE_VAR_PTR_AND_EXTRACT_RESULT_IF_NECESSARY(opline->op1.var);
@@ -2174,7 +2174,7 @@ ZEND_VM_HANDLER(88, ZEND_FETCH_OBJ_RW, VAR|UNUSED|THIS|CV, CONST|TMPVAR|CV, CACH
 	container = GET_OP1_OBJ_ZVAL_PTR_PTR_UNDEF(BP_VAR_RW);
 	property = GET_OP2_ZVAL_PTR(BP_VAR_R);
 	result = EX_VAR(opline->result.var);
-	zend_fetch_property_address(result, container, OP1_TYPE, property, OP2_TYPE, ((OP2_TYPE == IS_CONST) ? CACHE_ADDR(opline->extended_value) : NULL), BP_VAR_RW, 0, 1 OPLINE_CC EXECUTE_DATA_CC);
+	zend_fetch_property_address(result, container, OP1_TYPE, property, OP2_TYPE, ((OP2_TYPE == IS_CONST) ? CACHE_ADDR(opline->extended_value) : NULL), BP_VAR_RW, 0 OPLINE_CC EXECUTE_DATA_CC);
 	FREE_OP2();
 	if (OP1_TYPE == IS_VAR) {
 		FREE_VAR_PTR_AND_EXTRACT_RESULT_IF_NECESSARY(opline->op1.var);
@@ -2321,7 +2321,7 @@ ZEND_VM_HANDLER(97, ZEND_FETCH_OBJ_UNSET, VAR|UNUSED|THIS|CV, CONST|TMPVAR|CV, C
 	container = GET_OP1_OBJ_ZVAL_PTR_PTR_UNDEF(BP_VAR_UNSET);
 	property = GET_OP2_ZVAL_PTR(BP_VAR_R);
 	result = EX_VAR(opline->result.var);
-	zend_fetch_property_address(result, container, OP1_TYPE, property, OP2_TYPE, ((OP2_TYPE == IS_CONST) ? CACHE_ADDR(opline->extended_value) : NULL), BP_VAR_UNSET, 0, 1 OPLINE_CC EXECUTE_DATA_CC);
+	zend_fetch_property_address(result, container, OP1_TYPE, property, OP2_TYPE, ((OP2_TYPE == IS_CONST) ? CACHE_ADDR(opline->extended_value) : NULL), BP_VAR_UNSET, 0 OPLINE_CC EXECUTE_DATA_CC);
 	FREE_OP2();
 	if (OP1_TYPE == IS_VAR) {
 		FREE_VAR_PTR_AND_EXTRACT_RESULT_IF_NECESSARY(opline->op1.var);