tcp: verify the checksum of the first data segment in a new connection
authorFrank van der Linden <fllinden@amazon.com>
Tue, 12 Jun 2018 23:09:37 +0000 (23:09 +0000)
committerDavid S. Miller <davem@davemloft.net>
Fri, 15 Jun 2018 00:04:41 +0000 (17:04 -0700)
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.

Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp_ipv4.c
net/ipv6/tcp_ipv6.c

index fed3f1c6616708997f621535efe9412e4afa0a50..bea17f1e8302585d70c1e0108ae1c33d149230d8 100644 (file)
@@ -1730,6 +1730,10 @@ process:
                        reqsk_put(req);
                        goto discard_it;
                }
                        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;
                if (unlikely(sk->sk_state != TCP_LISTEN)) {
                        inet_csk_reqsk_queue_drop_and_put(sk, req);
                        goto lookup;
index b620d9b72e595ba4390b3e02ff8a0bbafa49eebe..7efa9fd7e1094dc43ca464e5c6f06ea36031d476 100644 (file)
@@ -1479,6 +1479,10 @@ process:
                        reqsk_put(req);
                        goto discard_it;
                }
                        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;
                if (unlikely(sk->sk_state != TCP_LISTEN)) {
                        inet_csk_reqsk_queue_drop_and_put(sk, req);
                        goto lookup;