pkgsrc/lang/python24/patches/patch-bh
drochner 20cca7e4a5 also apply upstream svn rev.65262, fixes overflow checks in memory
allocation (CVE-2008-3142), ride on PKGREVISION bump some minutes ago
2008-08-05 10:45:45 +00:00

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2.7 KiB
Text

$NetBSD: patch-bh,v 1.1 2008/08/05 10:45:45 drochner Exp $
--- Include/pymem.h.orig 2008-03-02 20:20:32.000000000 +0100
+++ Include/pymem.h
@@ -66,8 +66,12 @@ PyAPI_FUNC(void) PyMem_Free(void *);
for malloc(0), which would be treated as an error. Some platforms
would return a pointer with no memory behind it, which would break
pymalloc. To solve these problems, allocate an extra byte. */
-#define PyMem_MALLOC(n) malloc((n) ? (n) : 1)
-#define PyMem_REALLOC(p, n) realloc((p), (n) ? (n) : 1)
+/* Returns NULL to indicate error if a negative size or size larger than
+ Py_ssize_t can represent is supplied. Helps prevents security holes. */
+#define PyMem_MALLOC(n) (((n) < 0 || (n) > INT_MAX) ? NULL \
+ : malloc((n) ? (n) : 1))
+#define PyMem_REALLOC(p, n) (((n) < 0 || (n) > INT_MAX) ? NULL \
+ : realloc((p), (n) ? (n) : 1))
#endif /* PYMALLOC_DEBUG */
@@ -80,24 +84,31 @@ PyAPI_FUNC(void) PyMem_Free(void *);
* Type-oriented memory interface
* ==============================
*
- * These are carried along for historical reasons. There's rarely a good
- * reason to use them anymore (you can just as easily do the multiply and
- * cast yourself).
+ * Allocate memory for n objects of the given type. Returns a new pointer
+ * or NULL if the request was too large or memory allocation failed. Use
+ * these macros rather than doing the multiplication yourself so that proper
+ * overflow checking is always done.
*/
#define PyMem_New(type, n) \
- ( assert((n) <= PY_SIZE_MAX / sizeof(type)) , \
+ ( ((n) > INT_MAX / sizeof(type)) ? NULL : \
( (type *) PyMem_Malloc((n) * sizeof(type)) ) )
#define PyMem_NEW(type, n) \
- ( assert((n) <= PY_SIZE_MAX / sizeof(type)) , \
+ ( ((n) > INT_MAX / sizeof(type)) ? NULL : \
( (type *) PyMem_MALLOC((n) * sizeof(type)) ) )
+/*
+ * The value of (p) is always clobbered by this macro regardless of success.
+ * The caller MUST check if (p) is NULL afterwards and deal with the memory
+ * error if so. This means the original value of (p) MUST be saved for the
+ * caller's memory error handler to not lose track of it.
+ */
#define PyMem_Resize(p, type, n) \
- ( assert((n) <= PY_SIZE_MAX / sizeof(type)) , \
- ( (p) = (type *) PyMem_Realloc((p), (n) * sizeof(type)) ) )
+ ( (p) = ((n) > INT_MAX / sizeof(type)) ? NULL : \
+ (type *) PyMem_Realloc((p), (n) * sizeof(type)) )
#define PyMem_RESIZE(p, type, n) \
- ( assert((n) <= PY_SIZE_MAX / sizeof(type)) , \
- ( (p) = (type *) PyMem_REALLOC((p), (n) * sizeof(type)) ) )
+ ( (p) = ((n) > INT_MAX / sizeof(type)) ? NULL : \
+ (type *) PyMem_REALLOC((p), (n) * sizeof(type)) )
/* In order to avoid breaking old code mixing PyObject_{New, NEW} with
PyMem_{Del, DEL} and PyMem_{Free, FREE}, the PyMem "release memory"