Re: AUDIT: copy_from_user is a deathtrap.

Alan Cox
2002-05-17T12:25:30Z

> > I would much rather fix these instances than add yet another
> > interface.
>
> I'll accept that if someone's volunteering to audit the kernel for
> them every six months.
>
> Sorry I wasn't clear: I'm saying *replace*, not add,

Replace requires you audit every single use, and then work out how to
handle those that do care about the length and the point it faulted. From
what I've seen of the stuff that has been fixed we have a mix of the
following

1. Misports of ancient verify_* code - eg the serial ones
2. Not checking the return code - 100% legal and standards compliant

I've seen very few that have other screwups. In fact I've seen far more
incorrect uses of kmalloc with a user passed input field, kmalloc with
maths overflows, copy*user with maths overflows and the like

Alan