Re: Add Morton,Peter and David for discussion//Re: [PATCH -next] uprobes: fix two zero old_folio bugs in __replace_page()

[Tong Tiangen]

在 2025/2/20 16:38, David Hildenbrand 写道:
> On 20.02.25 03:31, Tong Tiangen wrote:
> > 在 2025/2/20 0:12, David Hildenbrand 写道:
> > > On 19.02.25 16:22, Oleg Nesterov wrote:
> > > > On 02/18, Tong Tiangen wrote:
> > > > > OK, Before your rewrite last merged, How about i change the 
> > > > > solution to
> > > > > just reject them immediately after get_user_page_vma_remote()？
> > > >
> > > > I agree, uprobe_write_opcode() should simply fail if
> > > > is_zero_page(old_page).
> > >
> > > Yes. That's currently only syzkaller that triggers it, not some sane use
> > > case.
> >
> > OK, change as follows:
> >
> > --- a/kernel/events/uprobes.c
> > +++ b/kernel/events/uprobes.c
> > @@ -506,6 +506,12 @@ int uprobe_write_opcode(struct arch_uprobe
> > *auprobe, struct mm_struct *mm,
> >           if (ret <= 0)
> >                   goto put_old;
> >
> > +       if (WARN(is_zero_page(old_page),
>
> This can likely be triggered by user space, so do not use WARN.

OK,thanks.

Hi Oleg, is that all right?

Thanks,
Tong.

>