From: Eric Dumazet edumazet@google.com
[ Upstream commit 7871f54e3deed68a27111dda162c4fe9b9c65f8f ]
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 edumazet@google.com Reported-and-bisected-by: Jaroslav Pulchart jaroslav.pulchart@gooddata.com Cc: Coco Li lixiaoyan@google.com Cc: Paolo Abeni pabeni@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 8e0fe85a647d..1b4abfb9a7a1 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -507,8 +507,9 @@ 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; }