https://github.com/python/cpython/commit/c498cd8bf81fc47acf2f1f702e8b3bc9bd4... commit: c498cd8bf81fc47acf2f1f702e8b3bc9bd4aed65 branch: 2.7 author: scoder <stefan_ml@behnel.de> committer: Serhiy Storchaka <storchaka@gmail.com> date: 2018-03-31T15:23:30+03:00 summary: bpo-31544: Fix a reference leak to 'self' after the previous target error handling fixes. (GH-6318) This change generally splits the xmlparser creation code into an unsafe part with "rollback" error handling and a safe "object initialisation done" part with normal decref cleanup. files: A Misc/NEWS.d/next/Library/2017-09-13-19-55-35.bpo-31455.beTh6t.rst M Modules/_elementtree.c diff --git a/Misc/NEWS.d/next/Library/2017-09-13-19-55-35.bpo-31455.beTh6t.rst b/Misc/NEWS.d/next/Library/2017-09-13-19-55-35.bpo-31455.beTh6t.rst new file mode 100644 index 000000000000..9ea3599ee0b0 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2017-09-13-19-55-35.bpo-31455.beTh6t.rst @@ -0,0 +1,2 @@ +The C accelerator module of ElementTree ignored exceptions raised when +looking up TreeBuilder target methods in XMLParser(). diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c index 7f0e60934003..1d316a1c91d2 100644 --- a/Modules/_elementtree.c +++ b/Modules/_elementtree.c @@ -2575,14 +2575,24 @@ xmlparser(PyObject* self_, PyObject* args, PyObject* kw) return NULL; } + ALLOC(sizeof(XMLParserObject), "create expatparser"); + + /* Init to NULL to keep the error handling below manageable. */ + self->target = + self->handle_xml = + self->handle_start = + self->handle_data = + self->handle_end = + self->handle_comment = + self->handle_pi = + self->handle_close = + NULL; + /* setup target handlers */ if (!target) { target = treebuilder_new(); if (!target) { - EXPAT(ParserFree)(self->parser); - PyObject_Del(self->names); - PyObject_Del(self->entity); - PyObject_Del(self); + Py_DECREF(self); return NULL; } } else @@ -2591,30 +2601,37 @@ xmlparser(PyObject* self_, PyObject* args, PyObject* kw) self->handle_xml = PyObject_GetAttrString(target, "xml"); if (ignore_attribute_error(self->handle_xml)) { + Py_DECREF(self); return NULL; } self->handle_start = PyObject_GetAttrString(target, "start"); if (ignore_attribute_error(self->handle_start)) { + Py_DECREF(self); return NULL; } self->handle_data = PyObject_GetAttrString(target, "data"); if (ignore_attribute_error(self->handle_data)) { + Py_DECREF(self); return NULL; } self->handle_end = PyObject_GetAttrString(target, "end"); if (ignore_attribute_error(self->handle_end)) { + Py_DECREF(self); return NULL; } self->handle_comment = PyObject_GetAttrString(target, "comment"); if (ignore_attribute_error(self->handle_comment)) { + Py_DECREF(self); return NULL; } self->handle_pi = PyObject_GetAttrString(target, "pi"); if (ignore_attribute_error(self->handle_pi)) { + Py_DECREF(self); return NULL; } self->handle_close = PyObject_GetAttrString(target, "close"); if (ignore_attribute_error(self->handle_close)) { + Py_DECREF(self); return NULL; } @@ -2650,8 +2667,6 @@ xmlparser(PyObject* self_, PyObject* args, PyObject* kw) ); #endif - ALLOC(sizeof(XMLParserObject), "create expatparser"); - return (PyObject*) self; }