[Python-Dev] can this overflow (list insertion)? (original) (raw)

Vladimir Marangozov Vladimir.Marangozov@inrialpes.fr
Sun, 13 Aug 2000 11:16:50 +0200 (CEST)

Tim Peters wrote:

I think it's more relying on the product of two other assumptions: (a) sizeof(int) >= 4, and (b) nobody is going to make a list with 2 billion elements in Python. But you're right, sooner or later that's going to bite us.

+1 on your patch, but frankly, if we reach a situation to be bitten by this overflow, chances are that we've already dumped core or will be very soon -- billions of objects = soon to be overflowing ob_refcnt integer counters. Py_None looks like a fine candidate for this.

Now I'm sure you're going to suggest again making the ob_refcnt a long, as you did before .

Suggest checking at the start of the routine instead:

if (self->obsize == INTMAX) { PyErrSetString(PyExcOverflowError, "cannot add more objects to list"); return -1; } Then the list isn't harmed.

-- Vladimir MARANGOZOV | Vladimir.Marangozov@inrialpes.fr http://sirac.inrialpes.fr/~marangoz | tel:(+33-4)76615277 fax:76615252