Re: AUDIT of 2.5.15 copy_to/from_user

Alan Cox
2002-05-19T18:00:59Z

> > > After that we always use __copy_from_user() and we trust it not to fail.
> > > Is this correct, or not?
>
> > This is correct
>
> Even if another thread unmaps the page we were trying to read from between
> the access_ok() and the actual copy?

Yes.

The only check done in access_ok on x86 is the 0xC0000000->0xFFFFFFFF check
with isnt affected by remappings.