On Sat, Apr 15, 2023 at 09:25:51AM +0900, Tetsuo Handa wrote: > On 2023/04/15 8:27, Lorenzo Stoakes wrote: > > diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c > > index f5bcb0dc6267..74d8d4007dec 100644 > > --- a/arch/arm64/kernel/mte.c > > +++ b/arch/arm64/kernel/mte.c > > @@ -437,8 +437,9 @@ static int __access_remote_tags(struct mm_struct *mm, unsigned long addr, > > struct page *page = NULL; > > > > ret = get_user_pages_remote(mm, addr, 1, gup_flags, &page, > > - &vma, NULL); > > - if (ret <= 0) > > + NULL); > > + vma = vma_lookup(mm, addr); > > + if (ret <= 0 || !vma) > > break; > > This conversion looks wrong. When get_user_pages_remote(&page) returned > 0, > put_page(page) is needed even if vma_lookup() returned NULL, isn't it? > You're right, though actually it's not possible for ret > 0 and vma != NULL because the GUP code requires the VMA to exist for it to have returned > 0. I was trying to be too cute here I think, actually we only want to be doing that lookup if the GUP succeeded in any case. Let me respin with a fix for this.
