Issue #1621: Avoid signed int negation overflow in audioop

This commit is contained in:
Martin Panter 2016-07-19 03:05:42 +00:00
parent e3d747496e
commit 6fb90905e2
2 changed files with 5 additions and 1 deletions

View file

@ -446,7 +446,9 @@ audioop_max_impl(PyObject *module, Py_buffer *fragment, int width)
return NULL;
for (i = 0; i < fragment->len; i += width) {
int val = GETRAWSAMPLE(width, fragment->buf, i);
if (val < 0) absval = (-val);
/* Cast to unsigned before negating. Unsigned overflow is well-
defined, but signed overflow is not. */
if (val < 0) absval = -(unsigned int)val;
else absval = val;
if (absval > max) max = absval;
}