tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0

[mirror_ubuntu-zesty-kernel.git] / net / ipv4 / tcp.c

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 53fa3a4275de758ac3408624b4faaf4b3843d904..cae2a73cd970b37089da628662a28ad039559977 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2298,6 +2298,10 @@ int tcp_disconnect(struct sock *sk, int flags)
        tcp_set_ca_state(sk, TCP_CA_Open);
        tcp_clear_retrans(tp);
        inet_csk_delack_init(sk);
+       /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0
+        * issue in __tcp_select_window()
+        */
+       icsk->icsk_ack.rcv_mss = TCP_MIN_MSS;
        tcp_init_send_head(sk);
        memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
        __sk_dst_reset(sk);