From: Xin Long lucien.xin@gmail.com
[ Upstream commit 10c678bd0a035ac2c64a9b26b222f20556227a53 ]
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: cf329aa42b66 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/udp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2173,7 +2173,7 @@ static int udp_queue_rcv_skb(struct sock __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; }