bounds check for bad data (thanks amaury)

2012-10-26 17:01:53 -07:00
parent a20879ffc8
commit 45c41494bf
2 changed files with 6 additions and 3 deletions
--- a/Python/codecs.c
+++ b/Python/codecs.c
@@ -821,9 +821,10 @@ PyCodec_SurrogatePassErrors(PyObject *exc)
        /* Try decoding a single surrogate character. If
           there are more, let the codec call us again. */
        p += start;
-        if ((p[0] & 0xf0) == 0xe0 ||
-            (p[1] & 0xc0) == 0x80 ||
-            (p[2] & 0xc0) == 0x80) {
+        if (strlen(p) > 2 &&
+            ((p[0] & 0xf0) == 0xe0 ||
+             (p[1] & 0xc0) == 0x80 ||
+             (p[2] & 0xc0) == 0x80)) {
            /* it's a three-byte code */
            ch = ((p[0] & 0x0f) << 12) + ((p[1] & 0x3f) << 6) + (p[2] & 0x3f);
            if (ch < 0xd800 || ch > 0xdfff)