Avoid using a stack allocated zend_function in Closure::call, to avoid prevent crashes on bailout

Having a stack allocated zend_function may cause crashes if the stack is polluted between bailout and the actual unwinding in zend_observer_fcall_end_all.

Signed-off-by: Bob Weinand <[email protected]>

Author: bwoebi

Zend/zend_closures.c

@@ -121,7 +121,6 @@ ZEND_METHOD(Closure, call)
 	zend_closure *closure;
 	zend_fcall_info fci;
 	zend_fcall_info_cache fci_cache;
-	zend_function my_function;
 	zend_object *newobj;
 	zend_class_entry *newclass;
 
@@ -142,55 +141,71 @@ ZEND_METHOD(Closure, call)
 		return;
 	}
 
+	fci_cache.called_scope = newclass;
+	fci_cache.object = fci.object = newobj;
+
+	fci.size = sizeof(fci);
+	ZVAL_OBJ(&fci.function_name, &closure->std);
+	ZVAL_UNDEF(&closure_result);
+	fci.retval = &closure_result;
+
 	if (closure->func.common.fn_flags & ZEND_ACC_GENERATOR) {
 		zval new_closure;
 		zend_create_closure(&new_closure, &closure->func, newclass, closure->called_scope, newthis);
 		closure = (zend_closure *) Z_OBJ(new_closure);
 		fci_cache.function_handler = &closure->func;
+
+		zend_call_function(&fci, &fci_cache);
+
+		/* copied upon generator creation */
+		GC_DELREF(&closure->std);
 	} else {
-		memcpy(&my_function, &closure->func, closure->func.type == ZEND_USER_FUNCTION ? sizeof(zend_op_array) : sizeof(zend_internal_function));
-		my_function.common.fn_flags &= ~ZEND_ACC_CLOSURE;
+		zend_function *my_function;
+		if (ZEND_USER_CODE(closure->func.type)) {
+			my_function = emalloc(sizeof(zend_op_array));
+			memcpy(my_function, &closure->func, sizeof(zend_op_array));
+		} else {
+			my_function = emalloc(sizeof(zend_internal_function));
+			memcpy(my_function, &closure->func, sizeof(zend_internal_function));
+		}
+		my_function->common.fn_flags &= ~ZEND_ACC_CLOSURE;
 		/* use scope of passed object */
-		my_function.common.scope = newclass;
+		my_function->common.scope = newclass;
 		if (closure->func.type == ZEND_INTERNAL_FUNCTION) {
-			my_function.internal_function.handler = closure->orig_internal_handler;
+			my_function->internal_function.handler = closure->orig_internal_handler;
 		}
-		fci_cache.function_handler = &my_function;
+		fci_cache.function_handler = my_function;
 
 		/* Runtime cache relies on bound scope to be immutable, hence we need a separate rt cache in case scope changed */
-		if (ZEND_USER_CODE(my_function.type)
+		if (ZEND_USER_CODE(my_function->type)
 		 && (closure->func.common.scope != newclass
 		  || (closure->func.common.fn_flags & ZEND_ACC_HEAP_RT_CACHE))) {
 			void *ptr;
 
-			my_function.op_array.fn_flags |= ZEND_ACC_HEAP_RT_CACHE;
-			ptr = emalloc(my_function.op_array.cache_size);
-			ZEND_MAP_PTR_INIT(my_function.op_array.run_time_cache, ptr);
-			memset(ptr, 0, my_function.op_array.cache_size);
+			my_function->op_array.fn_flags |= ZEND_ACC_HEAP_RT_CACHE;
+			ptr = emalloc(my_function->op_array.cache_size);
+			ZEND_MAP_PTR_INIT(my_function->op_array.run_time_cache, ptr);
+			memset(ptr, 0, my_function->op_array.cache_size);
 		}
-	}
 
-	fci_cache.called_scope = newclass;
-	fci_cache.object = fci.object = newobj;
+		zend_call_function(&fci, &fci_cache);
 
-	fci.size = sizeof(fci);
-	ZVAL_OBJ(&fci.function_name, &closure->std);
-	fci.retval = &closure_result;
+		if (ZEND_USER_CODE(my_function->type)) {
+			if (fci_cache.function_handler->common.fn_flags & ZEND_ACC_HEAP_RT_CACHE) {
+				efree(ZEND_MAP_PTR(my_function->op_array.run_time_cache));
+			}
+			efree_size(my_function, sizeof(zend_op_array));
+		} else {
+			efree_size(my_function, sizeof(zend_internal_function));
+		}
+	}
 
-	if (zend_call_function(&fci, &fci_cache) == SUCCESS && Z_TYPE(closure_result) != IS_UNDEF) {
+	if (Z_TYPE(closure_result) != IS_UNDEF) {
 		if (Z_ISREF(closure_result)) {
 			zend_unwrap_reference(&closure_result);
 		}
 		ZVAL_COPY_VALUE(return_value, &closure_result);
 	}
-
-	if (fci_cache.function_handler->common.fn_flags & ZEND_ACC_GENERATOR) {
-		/* copied upon generator creation */
-		GC_DELREF(&closure->std);
-	} else if (ZEND_USER_CODE(my_function.type)
-	 && (fci_cache.function_handler->common.fn_flags & ZEND_ACC_HEAP_RT_CACHE)) {
-		efree(ZEND_MAP_PTR(my_function.op_array.run_time_cache));
-	}
 }
 /* }}} */