Commit 1b1b43ee authored by Paolo Abeni's avatar Paolo Abeni Committed by Jakub Kicinski
Browse files

mptcp: fix data race around msk->first access 



The first subflow socket is accessed outside the msk socket lock
by mptcp_subflow_fail(), we need to annotate each write access
with WRITE_ONCE, but a few spots still lacks it.

Fixes: 76a13b31 ("mptcp: invoke MP_FAIL response when needed")
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7e8b88ec

net/mptcp/protocol.c

+3 −3
Original line number Diff line number Diff line
@@ -90,7 +90,7 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) 
	if (err)

		return err;



	msk->first = ssock->sk;

	WRITE_ONCE(msk->first, ssock->sk);

	WRITE_ONCE(msk->subflow, ssock);

	subflow = mptcp_subflow_ctx(ssock->sk);

	list_add(&subflow->node, &msk->conn_list);
@@ -2419,7 +2419,7 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, 
	sock_put(ssk);



	if (ssk == msk->first)

		msk->first = NULL;

		WRITE_ONCE(msk->first, NULL);



out:

	if (ssk == msk->last_snd)
@@ -2720,7 +2720,7 @@ static int __mptcp_init_sock(struct sock *sk) 
	WRITE_ONCE(msk->rmem_released, 0);

	msk->timer_ival = TCP_RTO_MIN;



	msk->first = NULL;

	WRITE_ONCE(msk->first, NULL);

	inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;

	WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));

	WRITE_ONCE(msk->allow_infinite_fallback, true);