tcp_metrics: properly set tp->snd_ssthresh in tcp_init_metrics()

[ Upstream commit 081480014a64a69d901f8ef1ffdd56d6085cf87e ]

We need to set tp->snd_ssthresh to TCP_INFINITE_SSTHRESH
in the case tcp_get_metrics() fails for some reason.

Fixes: 9ad7c049f0f7 ("tcp: RFC2988bis + taking RTT sample from 3WHS for the passive open side")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 4bfa2fb..0c03f56 100644 (file)
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -470,6 +470,10 @@ void tcp_init_metrics(struct sock *sk)
        u32 val, crtt = 0; /* cached RTT scaled by 8 */
 
        sk_dst_confirm(sk);
+       /* ssthresh may have been reduced unnecessarily during.
+        * 3WHS. Restore it back to its initial default.
+        */
+       tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
        if (!dst)
                goto reset;
 
@@ -489,11 +493,6 @@ void tcp_init_metrics(struct sock *sk)
                tp->snd_ssthresh = val;
                if (tp->snd_ssthresh > tp->snd_cwnd_clamp)
                        tp->snd_ssthresh = tp->snd_cwnd_clamp;
-       } else {
-               /* ssthresh may have been reduced unnecessarily during.
-                * 3WHS. Restore it back to its initial default.
-                */
-               tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
        }
        val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
        if (val && tp->reordering != val)