Re: [PATCH v5 bpf-next 01/10] lib/buildid: harden build ID parsing logic

[Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>]

On Mon, Aug 12, 2024 at 5:52 PM Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
>
> > @@ -152,6 +160,10 @@ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id,
> >       page = find_get_page(vma->vm_file->f_mapping, 0);
> >       if (!page)
> >               return -EFAULT; /* page not mapped */
> > +     if (!PageUptodate(page)) {
> > +             put_page(page);
> > +             return -EFAULT;
> > +     }
>
> That change is not described. As I understand it might prevent reading
> previous data in the page or maybe junk under an IO error? Anyways I guess it's a
> good change.