Re: [PATCH net-next 1/5] virtio_net: Fix an unsafe reference to the page chain

[Liang Chen]

On Fri, May 26, 2023 at 2:39 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> On Fri, May 26, 2023 at 1:46 PM Liang Chen <liangchen.linux@xxxxxxxxx> wrote:
> >
> > "private" of buffer page is currently used for big mode to chain pages.
> > But in mergeable mode, that offset of page could mean something else,
> > e.g. when page_pool page is used instead. So excluding mergeable mode to
> > avoid such a problem.
>
> If this issue happens only in the case of page_pool, it would be
> better to squash it there.
>
> Thanks

Sure, thanks!


>
> >
> > Signed-off-by: Liang Chen <liangchen.linux@xxxxxxxxx>
> > ---
> >  drivers/net/virtio_net.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 5a7f7a76b920..c5dca0d92e64 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -497,7 +497,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> >                         return NULL;
> >
> >                 page = (struct page *)page->private;
> > -               if (page)
> > +               if (!vi->mergeable_rx_bufs && page)
> >                         give_pages(rq, page);
> >                 goto ok;
> >         }
> > --
> > 2.31.1
> >
>