Re: [2/3] gso: Handle new frag_list of frags GRO packets

Herbert Xu
2013-11-11T18:54:42Z

On Thu, Nov 07, 2013 at 06:16:44PM +0000, Ben Hutchings wrote:
> On Thu, 2013-11-07 at 15:06 +0800, Herbert Xu wrote:
> > Recently GRO started generating packets with frag_lists of frags.
> > This was not handled by GSO, thus leading to a crash.
> >
> > Thankfully these packets are of a regular form and are easy to
> > handle. This patch handles them by calling skb_segment for each
> > frag_list entry. The depth of recursion is limited to just one.
> >
> > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> >
> > diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> > index 88b7dc6..bcc3f1c 100644
> > --- a/net/core/skbuff.c
> > +++ b/net/core/skbuff.c
> [...]
> > @@ -2855,8 +2853,40 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
> > nskb->data - tnl_hlen,
> > doffset + tnl_hlen);
> >
> > - if (fskb != skb_shinfo(skb)->frag_list)
> > - goto perform_csum_check;
> > + if (fskb != skb_shinfo(skb)->frag_list) {
> > + struct sk_buff *nsegs;
> > +
> > + if (nskb->len == len + doffset)
> > + goto perform_csum_check;
> > +
> > + SKB_FRAG_ASSERT(nskb);
> > +
> > + __skb_pull(nskb, doffset);
> > + skb_shinfo(nskb)->gso_size = mss;
> > + nsegs = skb_segment(nskb, features);
> > +
> > + err = PTR_ERR(nsegs);
> > + if (IS_ERR(nsegs)) {
> > + kfree(nskb);
>
> Should be kfree_skb().

Thanks for catching this and I have incorporated this into the
newer (albeit completely different) version of the patch.
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt