Re: [ubuntu-hardened] Add overflow protection to kref

From: Alexey Dobriyan
Date: Fri Feb 17 2012 - 01:33:59 EST


On Thu, Feb 16, 2012 at 09:48:38PM -0500, David Windsor wrote:
> <snip>
>
> >>
> >> I have yet to see a patch, so why are we arguing about this?  :)
> >>
> >> Again, I don't know of any kref overflows that have ever happened, so
> >> trying to "protect" this type of thing, seems odd to me.
> >
> > Well, I think the issue was to protect counting things (which seems to
> > be what PaX was after originally), and that kref seemed like the place
> > to put it. I'll let David take it further.
> >
>
> Patches are forthcoming that will first introduce overflow protection
> to kref.

Patches have already been posted:
http://marc.info/?l=linux-kernel&m=132337541830590&w=4
They were dropped for various (uninteresting) reasons, though.

> Once that's in place, I'll move a few refcount users from
> atomic_t to kref as a reference for other subsystems;

This sucks because dtor argument is mandatory.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/