On Sun, Jul 17, 2022 at 7:25 PM Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote:
>
> On 2022/7/17 7:06, Andrew Morton wrote:
> > On Thu, 14 Jul 2022 17:59:53 +0800 Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote:
> >
> >> On 2022/7/14 1:23, Andrew Morton wrote:
> >>> On Tue, 12 Jul 2022 21:05:42 +0800 Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote:
> >>>
> >>>> In MCOPY_ATOMIC_CONTINUE case with a non-shared VMA, pages in the page
> >>>> cache are installed in the ptes. But hugepage_add_new_anon_rmap is called
> >>>> for them mistakenly because they're not vm_shared. This will corrupt the
> >>>> page->mapping used by page cache code.
> >>>
> >>> Well that sounds bad. And theories on why this has gone unnoticed for
> >>> over a year? I assume this doesn't have coverage in our selftests?
> >>
> >> As discussed in another thread, when minor fault handling is proposed, only
> >> VM_SHARED vma is expected to be supported
> >
> > So... do we feel that this fix should be backported? And if so, is
> > there a suitable commit for the Fixes:?
>
> I tend to backport this fix. And I think the Fixes tag in this patch should be suitable,
> i.e. Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl").
Agreed, it is worth backporting.
>
> Thanks.
>
> > .
> >
>
