Commit 917944da authored by Mat Martineau's avatar Mat Martineau Committed by David S. Miller
Browse files

mptcp: Consistently use READ_ONCE/WRITE_ONCE with msk->ack_seq 



The msk->ack_seq value is sometimes read without the msk lock held, so
make proper use of READ_ONCE and WRITE_ONCE.

Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4972c6cc

net/mptcp/options.c

+2 −2
Original line number Diff line number Diff line
@@ -518,11 +518,11 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, 


	if (subflow->use_64bit_ack) {

		ack_size = TCPOLEN_MPTCP_DSS_ACK64;

		opts->ext_copy.data_ack = msk->ack_seq;

		opts->ext_copy.data_ack = READ_ONCE(msk->ack_seq);

		opts->ext_copy.ack64 = 1;

	} else {

		ack_size = TCPOLEN_MPTCP_DSS_ACK32;

		opts->ext_copy.data_ack32 = (uint32_t)(msk->ack_seq);

		opts->ext_copy.data_ack32 = (uint32_t)READ_ONCE(msk->ack_seq);

		opts->ext_copy.ack64 = 0;

	}

	opts->ext_copy.use_ack = 1;

net/mptcp/protocol.c

+4 −4
Original line number Diff line number Diff line
@@ -123,7 +123,7 @@ static void __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, 


	skb_ext_reset(skb);

	skb_orphan(skb);

	msk->ack_seq += copy_len;

	WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len);



	tail = skb_peek_tail(&sk->sk_receive_queue);

	if (offset == 0 && tail) {
@@ -261,7 +261,7 @@ static void mptcp_check_data_fin(struct sock *sk) 
	if (mptcp_pending_data_fin(sk, &rcv_data_fin_seq)) {

		struct mptcp_subflow_context *subflow;



		msk->ack_seq++;

		WRITE_ONCE(msk->ack_seq, msk->ack_seq + 1);

		WRITE_ONCE(msk->rcv_data_fin, 0);



		sk->sk_shutdown |= RCV_SHUTDOWN;
@@ -1720,7 +1720,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk, 
		msk->remote_key = mp_opt->sndr_key;

		mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq);

		ack_seq++;

		msk->ack_seq = ack_seq;

		WRITE_ONCE(msk->ack_seq, ack_seq);

	}



	sock_reset_flag(nsk, SOCK_RCU_FREE);
@@ -2072,7 +2072,7 @@ bool mptcp_finish_join(struct sock *sk) 
	parent_sock = READ_ONCE(parent->sk_socket);

	if (parent_sock && !sk->sk_socket)

		mptcp_sock_graft(sk, parent_sock);

	subflow->map_seq = msk->ack_seq;

	subflow->map_seq = READ_ONCE(msk->ack_seq);

	return true;

}

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