From 69c0cab120a85471054614418b447349caba22d7 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 17 Nov 2009 05:18:18 -0800 Subject: [PATCH] gro: Fix illegal merging of trailer trash When we've merged skb's with page frags, and subsequently receive a trailer skb (< MSS) that is not completely non-linear (this can occur on Intel NICs if the packet size falls below the threshold), GRO ends up producing an illegal GSO skb with a frag_list. This is harmless unless the skb is then forwarded through an interface that requires software GSO, whereupon the GSO code will BUG. This patch detects this case in GRO and avoids merging the trailer skb. Reported-by: Mark Wagner Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/core/skbuff.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 80a9616..ec85681 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2701,7 +2701,8 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) NAPI_GRO_CB(skb)->free = 1; goto done; - } + } else if (skb_gro_len(p) != pinfo->gso_size) + return -E2BIG; headroom = skb_headroom(p); nskb = netdev_alloc_skb(p->dev, headroom + skb_gro_offset(p)); -- 1.8.2.3