mptcp: Return EPIPE if sending is shut down during a sendmsg
A MPTCP socket where sending has been shut down should not attempt to
send additional data, since DATA_FIN has already been sent.
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 2891ae8..b3c3dbc 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -748,6 +748,11 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
restart:
mptcp_clean_una(sk);
+ if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) {
+ ret = -EPIPE;
+ goto out;
+ }
+
wait_for_sndbuf:
__mptcp_flush_join_list(msk);
ssk = mptcp_subflow_get_send(msk);