The patch below does not apply to the 5.11-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e0be4931f3fee2e04dec4013ea4f27ec2db8556f Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@xxxxxxxxx>
Date: Thu, 4 Mar 2021 13:32:08 -0800
Subject: [PATCH] mptcp: reset last_snd on subflow close
Send logic caches last active subflow in the msk, so it needs to be
cleared when the cached subflow is closed.
Fixes: d5f49190def61c ("mptcp: allow picking different xmit subflows")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/155
Reported-by: Christoph Paasch <cpaasch@xxxxxxxxx>
Acked-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index c5d5e68940ea..7362a536cbc0 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2126,6 +2126,8 @@ static struct sock *mptcp_subflow_get_retrans(const struct mptcp_sock *msk)
static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
struct mptcp_subflow_context *subflow)
{
+ struct mptcp_sock *msk = mptcp_sk(sk);
+
list_del(&subflow->node);
lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
@@ -2154,6 +2156,9 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
release_sock(ssk);
sock_put(ssk);
+
+ if (ssk == msk->last_snd)
+ msk->last_snd = NULL;
}
void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
