Issue #5387: Fixed mmap.move crash by integer overflow.

diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index 2dd76ad9ff676167e5f84c34cf890b4a51d906cf..b8998ea13d847fd7d04bb5f298cd54f42858e256 100644 (file)
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -339,6 +339,23 @@ class MmapTests(unittest.TestCase):
         mf.close()
         f.close()
 
+        # more excessive test
+        data = "0123456789"
+        for dest in range(len(data)):
+            for src in range(len(data)):
+                for count in range(len(data) - max(dest, src)):
+                    expected = data[:dest] + data[src:src+count] + data[dest+count:]
+                    m = mmap.mmap(-1, len(data))
+                    m[:] = data
+                    m.move(dest, src, count)
+                    self.assertEqual(m[:], expected)
+                    m.close()
+
+        # should not crash
+        m = mmap.mmap(-1, 1)
+        self.assertRaises(ValueError, m.move, 1, 1, -1)
+        m.close()
+
     def test_anonymous(self):
         # anonymous mmap.mmap(-1, PAGE)
         m = mmap.mmap(-1, PAGESIZE)

diff --git a/Misc/NEWS b/Misc/NEWS
index 97753ad2280f971da3ee55045dfb94f8229bcdef..a7925706c051a09266cc37fa36579d4f29cff570 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -199,6 +199,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #5387: Fixed mmap.move crash by integer overflow.
+
 - Issue #5261: Patch multiprocessing's semaphore.c to support context
   manager use: "with multiprocessing.Lock()" works now.
 

diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 95dcfbe630564a9c52b2b24d85827a727ffcb91e..d191c1e6fb122ed47e6113834052508f06db3913 100644 (file)
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -612,10 +612,8 @@ mmap_move_method(mmap_object *self, PyObject *args)
                return NULL;
        } else {
                /* bounds check the values */
-               if (/* end of source after end of data?? */
-                       ((src+count) > self->size)
-                       /* dest will fit? */
-                       || (dest+count > self->size)) {
+               unsigned long pos = src > dest ? src : dest;
+               if (self->size >= pos && count > self->size - pos) {
                        PyErr_SetString(PyExc_ValueError,
                                        "source or destination out of range");
                        return NULL;