- Patch #1541585: fix buffer overrun when performing repr() on
a unicode string in a build with wide unicode (UCS-4) support.
I will forward port to 2.6. Can someone backport to 2.4?
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index d93f780..8908745 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -2040,7 +2040,28 @@
static const char *hexdigit = "0123456789abcdef";
- repr = PyString_FromStringAndSize(NULL, 2 + 6*size + 1);
+ /* Initial allocation is based on the longest-possible unichr
+ escape.
+
+ In wide (UTF-32) builds '\U00xxxxxx' is 10 chars per source
+ unichr, so in this case it's the longest unichr escape. In
+ narrow (UTF-16) builds this is five chars per source unichr
+ since there are two unichrs in the surrogate pair, so in narrow
+ (UTF-16) builds it's not the longest unichr escape.
+
+ In wide or narrow builds '\uxxxx' is 6 chars per source unichr,
+ so in the narrow (UTF-16) build case it's the longest unichr
+ escape.
+ */
+
+ repr = PyString_FromStringAndSize(NULL,
+ 2
+#ifdef Py_UNICODE_WIDE
+ + 10*size
+#else
+ + 6*size
+#endif
+ + 1);
if (repr == NULL)
return NULL;
@@ -2065,15 +2086,6 @@
#ifdef Py_UNICODE_WIDE
/* Map 21-bit characters to '\U00xxxxxx' */
else if (ch >= 0x10000) {
- Py_ssize_t offset = p - PyString_AS_STRING(repr);
-
- /* Resize the string if necessary */
- if (offset + 12 > PyString_GET_SIZE(repr)) {
- if (_PyString_Resize(&repr, PyString_GET_SIZE(repr) + 100))
- return NULL;
- p = PyString_AS_STRING(repr) + offset;
- }
-
*p++ = '\\';
*p++ = 'U';
*p++ = hexdigit[(ch >> 28) & 0x0000000F];
@@ -2086,8 +2098,8 @@
*p++ = hexdigit[ch & 0x0000000F];
continue;
}
-#endif
- /* Map UTF-16 surrogate pairs to Unicode \UXXXXXXXX escapes */
+#else
+ /* Map UTF-16 surrogate pairs to '\U00xxxxxx' */
else if (ch >= 0xD800 && ch < 0xDC00) {
Py_UNICODE ch2;
Py_UCS4 ucs;
@@ -2112,6 +2124,7 @@
s--;
size++;
}
+#endif
/* Map 16-bit characters to '\uxxxx' */
if (ch >= 256) {