commit 4cde4bdcc86cb08ee3847500a172cc24eba37ffe
author INADA Naoki <methane@users.noreply.github.com> Mon Sep 04 12:31:41 2017 +0900
committer GitHub <noreply@github.com> Mon Sep 04 12:31:41 2017 +0900
tree cfc4c00f39f0cc6e9fec1e9756cf81c059ff9d6a
parent 990b2d043cdfaafc3378550f7d27259410a6b918

bpo-31095: Fix potential crash during GC (GH-3197)

(cherry picked from commit a6296d34a478b4f697ea9db798146195075d496c)

Objects/dictobject.c

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 9506067..a792b2d 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1076,6 +1076,7 @@
 {
     register PyDictEntry *ep;
     Py_ssize_t fill = mp->ma_fill;
+    /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(mp);
     Py_TRASHCAN_SAFE_BEGIN(mp)
     for (ep = mp->ma_table; fill > 0; ep++) {
@@ -2576,6 +2577,8 @@
 static void
 dictiter_dealloc(dictiterobject *di)
 {
+    /* bpo-31095: UnTrack is needed before calling any callbacks */
+    _PyObject_GC_UNTRACK(di);
     Py_XDECREF(di->di_dict);
     Py_XDECREF(di->di_result);
     PyObject_GC_Del(di);
@@ -2855,6 +2858,8 @@
 static void
 dictview_dealloc(dictviewobject *dv)
 {
+    /* bpo-31095: UnTrack is needed before calling any callbacks */
+    _PyObject_GC_UNTRACK(dv);
     Py_XDECREF(dv->dv_dict);
     PyObject_GC_Del(dv);
 }

Objects/setobject.c

diff --git a/Objects/setobject.c b/Objects/setobject.c
index b3ca643..0c69fac 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -549,6 +549,7 @@
 {
     register setentry *entry;
     Py_ssize_t fill = so->fill;
+    /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(so);
     Py_TRASHCAN_SAFE_BEGIN(so)
     if (so->weakreflist != NULL)
@@ -811,6 +812,8 @@
 static void
 setiter_dealloc(setiterobject *si)
 {
+    /* bpo-31095: UnTrack is needed before calling any callbacks */
+    _PyObject_GC_UNTRACK(si);
     Py_XDECREF(si->si_set);
     PyObject_GC_Del(si);
 }