From 917944da3bfc7cb5ac3af26725af3371d3a12db0 Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Tue, 29 Sep 2020 15:08:19 -0700 Subject: [PATCH] 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: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/options.c | 4 ++-- net/mptcp/protocol.c | 8 ++++---- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 7fa822b..120ef39 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -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; diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 365ba96..5d747c6a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -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; } -- 2.7.4