Commit 8555c6bf authored Aug 03, 2020 by Paolo Abeni Committed by David S. Miller Aug 03, 2020

mptcp: fix bogus sendmsg() return code under pressure



In case of memory pressure, mptcp_sendmsg() may call
sk_stream_wait_memory() after succesfully xmitting some
bytes. If the latter fails we currently return to the
user-space the error code, ignoring the succeful xmit.

Address the issue always checking for the xmitted bytes
before mptcp_sendmsg() completes.

Fixes: f296234c ("mptcp: Add handling of incoming MP_JOIN requests")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent f8deaea0

net/mptcp/protocol.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -984,7 +984,6 @@ wait_for_sndbuf:

		mptcp_set_timeout(sk, ssk);
		if (copied) {
		ret = copied;
		tcp_push(ssk, msg->msg_flags, mss_now, tcp_sk(ssk)->nonagle,
		size_goal);

		@@ -997,7 +996,7 @@ wait_for_sndbuf:
		release_sock(ssk);
		out:
		release_sock(sk);
		return ret;
		return copied ? : ret;
		}

		static void mptcp_wait_data(struct sock sk, long timeo)

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