[PATCH AUTOSEL 6.12 068/107] mptcp: annotate data-races around subflow->fully_established
flat view
DORMANTno replies
REVIEWED: 1 (1M)
From: Sasha Levin <sashal@kernel.org>
Date: 2024-11-24 13:37:14
Also in:
lkml, mptcp, stable
Subsystem:
networking [general], networking [mptcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthieu Baerts, Mat Martineau, Linus Torvalds
1 review trailer (1 from subsystem maintainers).
From: Gang Yan <redacted> [ Upstream commit 581c8cbfa934aaa555daa4e843242fcecc160f05 ] We introduce the same handling for potential data races with the 'fully_established' flag in subflow as previously done for msk->fully_established. Additionally, we make a crucial change: convert the subflow's 'fully_established' from 'bit_field' to 'bool' type. This is necessary because methods for avoiding data races don't work well with 'bit_field'. Specifically, the 'READ_ONCE' needs to know the size of the variable being accessed, which is not supported in 'bit_field'. Also, 'test_bit' expect the address of 'bit_field'. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/516 Signed-off-by: Gang Yan <redacted> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20241021-net-next-mptcp-misc-6-13-v1-2-1ef02746504a@kernel.org (local) Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- net/mptcp/diag.c | 2 +- net/mptcp/options.c | 4 ++-- net/mptcp/protocol.c | 2 +- net/mptcp/protocol.h | 6 +++--- net/mptcp/subflow.c | 4 ++-- 5 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/net/mptcp/diag.c b/net/mptcp/diag.c
index 2d3efb405437d..02205f7994d75 100644
--- a/net/mptcp/diag.c
+++ b/net/mptcp/diag.c@@ -47,7 +47,7 @@ static int subflow_get_info(struct sock *sk, struct sk_buff *skb) flags |= MPTCP_SUBFLOW_FLAG_BKUP_REM; if (sf->request_bkup) flags |= MPTCP_SUBFLOW_FLAG_BKUP_LOC; - if (sf->fully_established) + if (READ_ONCE(sf->fully_established)) flags |= MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED; if (sf->conn_finished) flags |= MPTCP_SUBFLOW_FLAG_CONNECTED;
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 370c3836b7712..1603b3702e220 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c@@ -461,7 +461,7 @@ static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb, return false; /* MPC/MPJ needed only on 3rd ack packet, DATA_FIN and TCP shutdown take precedence */ - if (subflow->fully_established || snd_data_fin_enable || + if (READ_ONCE(subflow->fully_established) || snd_data_fin_enable || subflow->snd_isn != TCP_SKB_CB(skb)->seq || sk->sk_state != TCP_ESTABLISHED) return false;
@@ -930,7 +930,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, /* here we can process OoO, in-window pkts, only in-sequence 4th ack * will make the subflow fully established */ - if (likely(subflow->fully_established)) { + if (likely(READ_ONCE(subflow->fully_established))) { /* on passive sockets, check for 3rd ack retransmission * note that msk is always set by subflow_syn_recv_sock() * for mp_join subflows
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 48d480982b787..47ee616f69c2d 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c@@ -3519,7 +3519,7 @@ static void schedule_3rdack_retransmission(struct sock *ssk) struct tcp_sock *tp = tcp_sk(ssk); unsigned long timeout; - if (mptcp_subflow_ctx(ssk)->fully_established) + if (READ_ONCE(mptcp_subflow_ctx(ssk)->fully_established)) return; /* reschedule with a timeout above RTT, as we must look only for drop */
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 568a72702b080..a93e661ef5c43 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h@@ -513,7 +513,6 @@ struct mptcp_subflow_context { request_bkup : 1, mp_capable : 1, /* remote is MPTCP capable */ mp_join : 1, /* remote is JOINing */ - fully_established : 1, /* path validated */ pm_notified : 1, /* PM hook called for established status */ conn_finished : 1, map_valid : 1,
@@ -532,10 +531,11 @@ struct mptcp_subflow_context { is_mptfo : 1, /* subflow is doing TFO */ close_event_done : 1, /* has done the post-closed part */ mpc_drop : 1, /* the MPC option has been dropped in a rtx */ - __unused : 8; + __unused : 9; bool data_avail; bool scheduled; bool pm_listener; /* a listener managed by the kernel PM? */ + bool fully_established; /* path validated */ u32 remote_nonce; u64 thmac; u32 local_nonce;
@@ -780,7 +780,7 @@ static inline bool __tcp_can_send(const struct sock *ssk) static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow) { /* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */ - if (subflow->request_join && !subflow->fully_established) + if (subflow->request_join && !READ_ONCE(subflow->fully_established)) return false; return __tcp_can_send(mptcp_subflow_tcp_sock(subflow));
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 6170f2fff71e4..860903e064225 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c@@ -800,7 +800,7 @@ void __mptcp_subflow_fully_established(struct mptcp_sock *msk, const struct mptcp_options_received *mp_opt) { subflow_set_remote_key(msk, subflow, mp_opt); - subflow->fully_established = 1; + WRITE_ONCE(subflow->fully_established, true); WRITE_ONCE(msk->fully_established, true); if (subflow->is_mptfo)
@@ -2062,7 +2062,7 @@ static void subflow_ulp_clone(const struct request_sock *req, } else if (subflow_req->mp_join) { new_ctx->ssn_offset = subflow_req->ssn_offset; new_ctx->mp_join = 1; - new_ctx->fully_established = 1; + WRITE_ONCE(new_ctx->fully_established, true); new_ctx->remote_key_valid = 1; new_ctx->backup = subflow_req->backup; new_ctx->request_bkup = subflow_req->request_bkup;
--
2.43.0