Re: [PATCH v2] binfmt_elf: Update READ_IMPLIES_EXEC logic for modern CPUs

[Kees Cook]

On Wed, Apr 24, 2019 at 1:54 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> On Wed, Apr 24, 2019 at 1:51 PM Will Deacon <will.deacon@xxxxxxx> wrote:
> > Don't you need to hack fs/compat_binfmt_elf.c to pick this up, or am I
> > missing some trick? Should just be something like below.
> >
> > Will
> >
> > --->8
> >
> > diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
> > index 15f6e96b3bd9..694bc3ee77eb 100644
> > --- a/fs/compat_binfmt_elf.c
> > +++ b/fs/compat_binfmt_elf.c
> > @@ -116,6 +116,11 @@
> >  #define        arch_setup_additional_pages compat_arch_setup_additional_pages
> >  #endif
> >
> > +#ifdef compat_elf_read_implies_exec
> > +#undef elf_read_implies_exec
> > +#define elf_read_implies_exec compat_elf_read_implies_exec
> > +#endif
> > +
> >  /*
> >   * Rename a few of the symbols that binfmt_elf.c will define.
> >   * These are all local so the names don't really matter, but it
>
> Argh. I thought I already saw stuff like this somewhere, but I think I
> must have been looking at some other compat silliness. I'll fix this
> and split up the series...

Andrew, can you please drop this patch from -mm for now? I'll pursue
these changes separately through x86 and arm64 trees.

Thanks!

-- 
Kees Cook