[Python-checkins] cpython (merge 3.5 -> default): Issue #27507: Merge overflow check from 3.5

[martin.panter]

https://hg.python.org/cpython/rev/646ad4894c32
changeset:   102398:646ad4894c32
parent:      102395:61bb66fe1fb7
parent:      102396:54cc0480904c
user:        Martin Panter <vadmium+py at gmail.com>
date:        Mon Jul 18 08:18:32 2016 +0000
summary:
  Issue #27507: Merge overflow check from 3.5

files:
  Misc/NEWS                 |   3 +++
  Objects/bytearrayobject.c |  12 +++++++++++-
  2 files changed, 14 insertions(+), 1 deletions(-)


diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Issue #27507: Add integer overflow check in bytearray.extend().  Patch by
+  Xiang Zhang.
+
 - Issue #27419: Standard __import__() no longer look up "__import__" in globals
   or builtins for importing submodules or "from import".  Fixed a crash if
   raise a warning about unabling to resolve package from __spec__ or
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -1642,7 +1642,17 @@
         Py_DECREF(item);
 
         if (len >= buf_size) {
-            buf_size = len + (len >> 1) + 1;
+            Py_ssize_t addition;
+            if (len == PY_SSIZE_T_MAX) {
+                Py_DECREF(it);
+                Py_DECREF(bytearray_obj);
+                return PyErr_NoMemory();
+            }
+            addition = len >> 1;
+            if (addition > PY_SSIZE_T_MAX - len - 1)
+                buf_size = PY_SSIZE_T_MAX;
+            else
+                buf_size = len + addition + 1;
             if (PyByteArray_Resize((PyObject *)bytearray_obj, buf_size) < 0) {
                 Py_DECREF(it);
                 Py_DECREF(bytearray_obj);

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