Re: [PATCH] uaccess: Disallow > INT_MAX copy sizes

From: Andrew Morton
Date: Tue Sep 24 2019 - 19:30:05 EST


On Mon, 23 Sep 2019 16:08:54 -0700 Kees Cook <keescook@xxxxxxxxxxxx> wrote:

> On Sun, Aug 25, 2019 at 04:18:56PM -0700, Kees Cook wrote:
> > As we've done with VFS, string operations, etc, reject usercopy sizes
> > larger than INT_MAX, which would be nice to have for catching bugs
> > related to size calculation overflows[1].
> >
> > This adds 10 bytes to x86_64 defconfig text and 1980 bytes to the data
> > section:
> >
> > text data bss dec hex filename
> > 19691167 5134320 1646664 26472151 193eed7 vmlinux.before
> > 19691177 5136300 1646664 26474141 193f69d vmlinux.after
> >
> > [1] https://marc.info/?l=linux-s390&m=156631939010493&w=2
> >
> > Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>
> ping! Andrew, can you take this?

It's in my post 5.4-rc1 pile.