From 7871f54e3deed68a27111dda162c4fe9b9c65f8f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 6 Jan 2023 14:25:23 +0000 Subject: [PATCH] gro: take care of DODGY packets Jaroslav reported a recent throughput regression with virtio_net caused by blamed commit. It is unclear if DODGY GSO packets coming from user space can be accepted by GRO engine in the future with minimal changes, and if there is any expected gain from it. In the meantime, make sure to detect and flush DODGY packets. Fixes: 5eddb24901ee ("gro: add support of (hw)gro packets to gro stack") Signed-off-by: Eric Dumazet Reported-and-bisected-by: Jaroslav Pulchart Cc: Coco Li Cc: Paolo Abeni Signed-off-by: David S. Miller --- net/core/gro.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/core/gro.c b/net/core/gro.c index fd8c6a7e8d3e..506f83d715f8 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -505,8 +505,9 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff NAPI_GRO_CB(skb)->count = 1; if (unlikely(skb_is_gso(skb))) { NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs; - /* Only support TCP at the moment. */ - if (!skb_is_gso_tcp(skb)) + /* Only support TCP and non DODGY users. */ + if (!skb_is_gso_tcp(skb) || + (skb_shinfo(skb)->gso_type & SKB_GSO_DODGY)) NAPI_GRO_CB(skb)->flush = 1; }