Commit 10c678bd authored Dec 07, 2020 by Xin Long Committed by David S. Miller Dec 07, 2020

udp: fix the proto value passed to ip_protocol_deliver_rcu for the segments



Guillaume noticed that: for segments udp_queue_rcv_one_skb() returns the
proto, and it should pass "ret" unmodified to ip_protocol_deliver_rcu().
Otherwize, with a negtive value passed, it will underflow inet_protos.

This can be reproduced with IPIP FOU:

  # ip fou add port 5555 ipproto 4
  # ethtool -K eth1 rx-gro-list on

Fixes: cf329aa4 ("udp: cope with UDP GRO packet misdirection")
Reported-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 61f54de2

net/ipv4/udp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2173,7 +2173,7 @@ static int udp_queue_rcv_skb(struct sock sk, struct sk_buff skb)
		__skb_pull(skb, skb_transport_offset(skb));
		ret = udp_queue_rcv_one_skb(sk, skb);
		if (ret > 0)
		ip_protocol_deliver_rcu(dev_net(skb->dev), skb, -ret);
		ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret);
		}
		return 0;
		}

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