[Python-checkins] cpython (3.5): Issue #23782: Fixed possible memory leak in _PyTraceback_Add() and exception

[serhiy.storchaka]

https://hg.python.org/cpython/rev/6b3be9f38f2a
changeset:   104529:6b3be9f38f2a
branch:      3.5
parent:      104524:14363cf42e15
user:        Serhiy Storchaka <storchaka at gmail.com>
date:        Tue Oct 18 13:23:18 2016 +0300
summary:
  Issue #23782: Fixed possible memory leak in _PyTraceback_Add() and exception
loss in PyTraceBack_Here().

files:
  Misc/NEWS          |   3 ++
  Python/traceback.c |  46 +++++++++++++++++++--------------
  2 files changed, 29 insertions(+), 20 deletions(-)


diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Issue #23782: Fixed possible memory leak in _PyTraceback_Add() and exception
+  loss in PyTraceBack_Here().
+
 - Issue #28379: Added sanity checks and tests for PyUnicode_CopyCharacters().
   Patch by Xiang Zhang.
 
diff --git a/Python/traceback.c b/Python/traceback.c
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -132,47 +132,53 @@
 int
 PyTraceBack_Here(PyFrameObject *frame)
 {
-    PyThreadState *tstate = PyThreadState_GET();
-    PyTracebackObject *oldtb = (PyTracebackObject *) tstate->curexc_traceback;
-    PyTracebackObject *tb = newtracebackobject(oldtb, frame);
-    if (tb == NULL)
+    PyObject *exc, *val, *tb, *newtb;
+    PyErr_Fetch(&exc, &val, &tb);
+    newtb = (PyObject *)newtracebackobject((PyTracebackObject *)tb, frame);
+    if (newtb == NULL) {
+        _PyErr_ChainExceptions(exc, val, tb);
         return -1;
-    tstate->curexc_traceback = (PyObject *)tb;
-    Py_XDECREF(oldtb);
+    }
+    PyErr_Restore(exc, val, newtb);
+    Py_XDECREF(tb);
     return 0;
 }
 
 /* Insert a frame into the traceback for (funcname, filename, lineno). */
 void _PyTraceback_Add(const char *funcname, const char *filename, int lineno)
 {
-    PyObject *globals = NULL;
-    PyCodeObject *code = NULL;
-    PyFrameObject *frame = NULL;
-    PyObject *exception, *value, *tb;
+    PyObject *globals;
+    PyCodeObject *code;
+    PyFrameObject *frame;
+    PyObject *exc, *val, *tb;
 
     /* Save and clear the current exception. Python functions must not be
        called with an exception set. Calling Python functions happens when
        the codec of the filesystem encoding is implemented in pure Python. */
-    PyErr_Fetch(&exception, &value, &tb);
+    PyErr_Fetch(&exc, &val, &tb);
 
     globals = PyDict_New();
     if (!globals)
-        goto done;
+        goto error;
     code = PyCode_NewEmpty(filename, funcname, lineno);
-    if (!code)
-        goto done;
+    if (!code) {
+        Py_DECREF(globals);
+        goto error;
+    }
     frame = PyFrame_New(PyThreadState_Get(), code, globals, NULL);
+    Py_DECREF(globals);
+    Py_DECREF(code);
     if (!frame)
-        goto done;
+        goto error;
     frame->f_lineno = lineno;
 
-    PyErr_Restore(exception, value, tb);
+    PyErr_Restore(exc, val, tb);
     PyTraceBack_Here(frame);
+    Py_DECREF(frame);
+    return;
 
-done:
-    Py_XDECREF(globals);
-    Py_XDECREF(code);
-    Py_XDECREF(frame);
+error:
+    _PyErr_ChainExceptions(exc, val, tb);
 }
 
 static PyObject *

-- 
Repository URL: https://hg.python.org/cpython