This is a note to let you know that I've just added the patch titled
tcp_metrics: properly set tp->snd_ssthresh in tcp_init_metrics()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tcp_metrics-properly-set-tp-snd_ssthresh-in-tcp_init.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1fb52480f7dc4a585d4960194fd0dc276f683d48
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri Sep 22 22:03:54 2023 +0000
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@xxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Acked-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 0275bf7570b4c..940f75df19358 100644
--- 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)
