From: Alexander Duyck Date: Mon, 2 May 2016 16:38:18 +0000 (-0700) Subject: gso: Only allow GSO_PARTIAL if we can checksum the inner protocol X-Git-Tag: v4.7-rc1~154^2~126^2~6 X-Git-Url: http://git.cascardo.info/?a=commitdiff_plain;h=36c983824b6f17b93258153ff5b05c33c34e44ba;p=cascardo%2Flinux.git gso: Only allow GSO_PARTIAL if we can checksum the inner protocol This patch addresses a possible issue that can occur if we get into any odd corner cases where we support TSO for a given protocol but not the checksum or scatter-gather offload. There are few drivers floating around that setup their tunnels this way and by enforcing the checksum piece we can avoid mangling any frames. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b8dd2d2e2256..5586be93632f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3080,8 +3080,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, unsigned int headroom; unsigned int len = head_skb->len; __be16 proto; - bool csum; - int sg = !!(features & NETIF_F_SG); + bool csum, sg; int nfrags = skb_shinfo(head_skb)->nr_frags; int err = -ENOMEM; int i = 0; @@ -3093,13 +3092,14 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, if (unlikely(!proto)) return ERR_PTR(-EINVAL); + sg = !!(features & NETIF_F_SG); csum = !!can_checksum_protocol(features, proto); /* GSO partial only requires that we trim off any excess that * doesn't fit into an MSS sized block, so take care of that * now. */ - if (features & NETIF_F_GSO_PARTIAL) { + if (sg && csum && (features & NETIF_F_GSO_PARTIAL)) { partial_segs = len / mss; if (partial_segs > 1) mss *= partial_segs;