python#4317: Fix an Array Bounds Read in imageop.rgb2rgb8.

amauryfa · amauryfa · commit a5f3ceb21eb6 · 2008-11-18T22:49:39.000Z
Backport of r67266
diff --git a/Lib/test/test_imageop.py b/Lib/test/test_imageop.py
@@ -13,6 +13,7 @@
 _VALUES = (1, 2, 2**10, 2**15-1, 2**15, 2**15+1, 2**31-2, 2**31-1)
 VALUES = tuple( -x for x in reversed(_VALUES) ) + (0,) + _VALUES
 AAAAA = "A" * 1024
+MAX_LEN = 2**20
 
 
 class InputValidationTests(unittest.TestCase):
@@ -24,7 +25,7 @@ def _check(self, name, size=None, *extra):
                 strlen = abs(width * height)
                 if size:
                     strlen *= size
-                if strlen < 1024:
+                if strlen < MAX_LEN:
                     data = "A" * strlen
                 else:
                     data = AAAAA
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -12,6 +12,8 @@ What's New in Python 2.4.6c1?
 Core and builtins
 -----------------
 
+- Issue #4317: Fixed a crash in the imageop.rgb2rgb8() function.
+
 - Issue #4230: Fix a crash when a class has a custom __getattr__ and an
   __getattribute__ method that deletes the __getattr__ attribute.
 
diff --git a/Modules/imageop.c b/Modules/imageop.c
@@ -590,7 +590,7 @@ imageop_rgb2rgb8(PyObject *self, PyObject *args)
 	if ( !PyArg_ParseTuple(args, "s#ii", &cp, &len, &x, &y) )
 		return 0;
 
-	if ( !check_multiply_size(len*4, x, "x", y, "y", 4) )
+	if ( !check_multiply_size(len, x, "x", y, "y", 4) )
 		return 0;
 	nlen = x*y;
 	if ( !check_multiply(nlen, x, y) )
