From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 2/2] virtio-net: Prevent NULL dereference Date: Mon, 26 Sep 2011 21:47:03 +0300 Message-ID: <20110926184703.GB22278@redhat.com> References: <1317058869-19276-1-git-send-email-levinsasha928@gmail.com> <1317058869-19276-2-git-send-email-levinsasha928@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, Rusty Russell , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org To: Sasha Levin Return-path: Received: from mx1.redhat.com ([209.132.183.28]:5769 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752375Ab1IZSqT (ORCPT ); Mon, 26 Sep 2011 14:46:19 -0400 Content-Disposition: inline In-Reply-To: <1317058869-19276-2-git-send-email-levinsasha928@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Sep 26, 2011 at 08:41:09PM +0300, Sasha Levin wrote: > This patch prevents a NULL dereference when the user has passed a length > longer than an actual buffer to virtio-net. > > Cc: Rusty Russell > Cc: "Michael S. Tsirkin" > Cc: virtualization@lists.linux-foundation.org > Cc: netdev@vger.kernel.org > Cc: kvm@vger.kernel.org > Signed-off-by: Sasha Levin Hmm, another protection against a buggy device, right? No problem with that, but let's discard the packet and print a disgnostic, so that the user can discover what happened. > --- > drivers/net/virtio_net.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 64e0717..8d32c1e 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -198,7 +198,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > len -= copy; > offset += copy; > > - while (len) { > + while (len && page) { > set_skb_frag(skb, page, offset, &len); > page = (struct page *)page->private; > offset = 0; > -- > 1.7.6.1