tcp: validate fin seq in closing states

Type: fix

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Id8673cff699cfdc1ac68797b9ab5cdf6f6b578a3

diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
index 182062f..912b193 100644 (file)
--- a/src/vnet/tcp/tcp_input.c
+++ b/src/vnet/tcp/tcp_input.c
@@ -2386,6 +2386,9 @@ tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
        case TCP_STATE_FIN_WAIT_2:
          if (vnet_buffer (b0)->tcp.data_len)
            error0 = tcp_segment_rcv (wrk, tc0, b0);
+         /* Don't accept out of order fins lower */
+         if (vnet_buffer (b0)->tcp.seq_end != tc0->rcv_nxt)
+           goto drop;
          break;
        case TCP_STATE_CLOSE_WAIT:
        case TCP_STATE_CLOSING: