Merged revisions 75141 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r75141 | mark.dickinson | 2009-09-29 20:01:06 +0100 (Tue, 29 Sep 2009) | 3 lines

  Issue #7019:  Unmarshalling of bad long data could produce unnormalized
  PyLongs.  Raise ValueError instead.
........

diff --git a/Lib/test/test_marshal.py b/Lib/test/test_marshal.py
index 6e3efe4a31776509942bf5a7c0d7db555b72f79d..66887859cd814c6d0835ca665f1b193251bd8967 100644 (file)
--- a/Lib/test/test_marshal.py
+++ b/Lib/test/test_marshal.py
@@ -212,6 +212,11 @@ class BugsTestCase(unittest.TestCase):
         testString = 'abc' * size
         marshal.dumps(testString)
 
+    def test_invalid_longs(self):
+        # Issue #7019: marshal.loads shouldn't produce unnormalized PyLongs
+        invalid_string = b'l\x02\x00\x00\x00\x00\x00\x00\x00'
+        self.assertRaises(ValueError, marshal.loads, invalid_string)
+
 
 def test_main():
     support.run_unittest(IntTestCase,

diff --git a/Misc/NEWS b/Misc/NEWS
index 75f6947f38aba6b962fdf2004442fdd4f8b08565..f54fbb767ac598840f8ce6aed87e60752f6c5d2f 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@ What's New in Python 3.2 Alpha 1?
 Core and Builtins
 -----------------
 
+- Issue #7019: Raise ValueError when unmarshalling bad long data, instead
+  of producing internally inconsistent Python longs.
+
 - Issue #6990: Fix threading.local subclasses leaving old state around
   after a reference cycle GC which could be recycled by new locals.
 

diff --git a/Python/marshal.c b/Python/marshal.c
index 54d19d5de33781cd8560e2e23f6bccca064ff7e7..256285b4268c8162de18c8fb8069c1963f667ab1 100644 (file)
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -553,7 +553,7 @@ static PyObject *
 r_PyLong(RFILE *p)
 {
        PyLongObject *ob;
-       int size, i, j, md;
+       int size, i, j, md, shorts_in_top_digit;
        long n;
        digit d;
 
@@ -566,7 +566,8 @@ r_PyLong(RFILE *p)
                return NULL;
        }
 
-       size = 1 + (ABS(n)-1) / PyLong_MARSHAL_RATIO;
+       size = 1 + (ABS(n) - 1) / PyLong_MARSHAL_RATIO;
+       shorts_in_top_digit = 1 + (ABS(n) - 1) % PyLong_MARSHAL_RATIO;
        ob = _PyLong_New(size);
        if (ob == NULL)
                return NULL;
@@ -583,12 +584,21 @@ r_PyLong(RFILE *p)
                ob->ob_digit[i] = d;
        }
        d = 0;
-       for (j=0; j < (ABS(n)-1)%PyLong_MARSHAL_RATIO + 1; j++) {
+       for (j=0; j < shorts_in_top_digit; j++) {
                md = r_short(p);
                if (md < 0 || md > PyLong_MARSHAL_BASE)
                        goto bad_digit;
+               /* topmost marshal digit should be nonzero */
+               if (md == 0 && j == shorts_in_top_digit - 1) {
+                       Py_DECREF(ob);
+                       PyErr_SetString(PyExc_ValueError,
+                               "bad marshal data (unnormalized long data)");
+                       return NULL;
+               }
                d += (digit)md << j*PyLong_MARSHAL_SHIFT;
        }
+       /* top digit should be nonzero, else the resulting PyLong won't be
+          normalized */
        ob->ob_digit[size-1] = d;
        return (PyObject *)ob;
   bad_digit: