commit 8042f4af29d91eb776b143105636bc8099b4b1bc
author Benjamin Peterson <benjamin@python.org> Sat Sep 11 16:03:33 2010 +0000
committer Benjamin Peterson <benjamin@python.org> Sat Sep 11 16:03:33 2010 +0000
tree ae50b4cdce369eca77775ce35da14c74d56b4483
parent 40f7e11f12590beb6486a40be8f9f60e5676c176

Merged revisions 84714 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r84714 | benjamin.peterson | 2010-09-11 11:02:03 -0500 (Sat, 11 Sep 2010) | 1 line

  check for NULL tp_as_mapping in PySequence_(Get/Set/Del)Slice #9834
........

Misc/NEWS

diff --git a/Misc/NEWS b/Misc/NEWS
index d716e47..3271861 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -105,6 +105,10 @@
 C-API
 -----
 
+- Issue #9834: Don't segfault in PySequence_GetSlice, PySequence_SetSlice, or
+  PySequence_DelSlice when the object doesn't have any mapping operations
+  defined.
+
 - Issue #5753: A new C API function, :cfunc:`PySys_SetArgvEx`, allows
   embedders of the interpreter to set sys.argv without also modifying
   sys.path.  This helps fix `CVE-2008-5983

Objects/abstract.c

diff --git a/Objects/abstract.c b/Objects/abstract.c
index 3698250..2d4f2e1 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1623,7 +1623,7 @@
     if (!s) return null_error();
 
     mp = s->ob_type->tp_as_mapping;
-    if (mp->mp_subscript) {
+    if (mp && mp->mp_subscript) {
         PyObject *res;
         PyObject *slice = _PySlice_FromIndices(i1, i2);
         if (!slice)
@@ -1701,7 +1701,7 @@
     }
 
     mp = s->ob_type->tp_as_mapping;
-    if (mp->mp_ass_subscript) {
+    if (mp && mp->mp_ass_subscript) {
         int res;
         PyObject *slice = _PySlice_FromIndices(i1, i2);
         if (!slice)
@@ -1726,7 +1726,7 @@
     }
 
     mp = s->ob_type->tp_as_mapping;
-    if (mp->mp_ass_subscript) {
+    if (mp && mp->mp_ass_subscript) {
         int res;
         PyObject *slice = _PySlice_FromIndices(i1, i2);
         if (!slice)