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@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e0be4931f3fee2e04dec4013ea4f27ec2db8556f Mon Sep 17 00:00:00 2001
From: Florian Westphal fw@strlen.de 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@apple.com Acked-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Matthieu Baerts matthieu.baerts@tessares.net Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net
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,