[Python-checkins] cpython (merge 3.5 -> default): Issue #24467: Fixed possible buffer over-read in bytearray. The bytearray

[serhiy.storchaka]

https://hg.python.org/cpython/rev/97a24bc714ec
changeset:   96720:97a24bc714ec
parent:      96714:f2f5d1c928eb
parent:      96719:942860bada14
user:        Serhiy Storchaka <storchaka at gmail.com>
date:        Mon Jun 29 21:18:55 2015 +0300
summary:
  Issue #24467: Fixed possible buffer over-read in bytearray. The bytearray
object now always allocates place for trailing null byte and it's buffer now
is always null-terminated.

files:
  Lib/test/test_bytes.py    |  19 ++++++++++++++++++-
  Misc/NEWS                 |   4 ++++
  Objects/bytearrayobject.c |   4 +++-
  3 files changed, 25 insertions(+), 2 deletions(-)


diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -1098,10 +1098,27 @@
         for i in range(100):
             b += b"x"
             alloc = b.__alloc__()
-            self.assertTrue(alloc >= len(b))
+            self.assertGreater(alloc, len(b))  # including trailing null byte
             if alloc not in seq:
                 seq.append(alloc)
 
+    def test_init_alloc(self):
+        b = bytearray()
+        def g():
+            for i in range(1, 100):
+                yield i
+                a = list(b)
+                self.assertEqual(a, list(range(1, len(a)+1)))
+                self.assertEqual(len(b), len(a))
+                self.assertLessEqual(len(b), i)
+                alloc = b.__alloc__()
+                self.assertGreater(alloc, len(b))  # including trailing null byte
+        b.__init__(g())
+        self.assertEqual(list(b), list(range(1, 100)))
+        self.assertEqual(len(b), 99)
+        alloc = b.__alloc__()
+        self.assertGreater(alloc, len(b))
+
     def test_extend(self):
         orig = b'hello'
         a = bytearray(orig)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -32,6 +32,10 @@
 Core and Builtins
 -----------------
 
+- Issue #24467: Fixed possible buffer over-read in bytearray. The bytearray
+  object now always allocates place for trailing null byte and it's buffer now
+  is always null-terminated.
+
 - Upgrade to Unicode 8.0.0.
 
 - Issue #24345: Add Py_tp_finalize slot for the stable ABI.
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -891,8 +891,10 @@
             goto error;
 
         /* Append the byte */
-        if (Py_SIZE(self) < self->ob_alloc)
+        if (Py_SIZE(self) + 1 < self->ob_alloc) {
             Py_SIZE(self)++;
+            PyByteArray_AS_STRING(self)[Py_SIZE(self)] = '\0';
+        }
         else if (PyByteArray_Resize((PyObject *)self, Py_SIZE(self)+1) < 0)
             goto error;
         PyByteArray_AS_STRING(self)[Py_SIZE(self)-1] = value;

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