On Wed, Jun 13, 2018 at 9:09 AM, Frank van der Linden <fllin...@amazon.com> wrote: > commit 079096f103fa ("tcp/dccp: install syn_recv requests into ehash > table") introduced an optimization for the handling of child sockets > created for a new TCP connection. > > But this optimization passes any data associated with the last ACK of the > connection handshake up the stack without verifying its checksum, because it > calls tcp_child_process(), which in turn calls tcp_rcv_state_process() > directly. These lower-level processing functions do not do any checksum > verification. > > Insert a tcp_checksum_complete call in the TCP_NEW_SYN_RECEIVE path to > fix this. > > Signed-off-by: Frank van der Linden <fllin...@amazon.com> > --- > net/ipv4/tcp_ipv4.c | 4 ++++ > net/ipv6/tcp_ipv6.c | 4 ++++ > 2 files changed, 8 insertions(+) > > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index f70586b..ef8cd0f 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -1689,6 +1689,10 @@ int tcp_v4_rcv(struct sk_buff *skb) > reqsk_put(req); > goto discard_it; > } > + if (tcp_checksum_complete(skb)) { > + reqsk_put(req); > + goto csum_error; > + } > if (unlikely(sk->sk_state != TCP_LISTEN)) { > inet_csk_reqsk_queue_drop_and_put(sk, req); > goto lookup; > diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c > index 6d664d8..5d4eb9d 100644 > --- a/net/ipv6/tcp_ipv6.c > +++ b/net/ipv6/tcp_ipv6.c > @@ -1475,6 +1475,10 @@ static int tcp_v6_rcv(struct sk_buff *skb) > reqsk_put(req); > goto discard_it; > } > + if (tcp_checksum_complete(skb)) { > + reqsk_put(req); > + goto csum_error; > + } > if (unlikely(sk->sk_state != TCP_LISTEN)) { > inet_csk_reqsk_queue_drop_and_put(sk, req); > goto lookup;
I've tested the IPv4 variant with some changes Tested-by: Balbir Singh <bsinghar...@gmail.com> Reviewed-by: Balbir Singh <bsinghar...@gmail.com> Balbir