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From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: Thu, 15 Feb 2024 19:25:32 +0100
Subject: [PATCH net 05/13] mptcp: fix data races on remote_id
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Message-Id: <20240215-upstream-net-20240215-misc-fixes-v1-5-8c01a55d8f6a@kernel.org>
References: <20240215-upstream-net-20240215-misc-fixes-v1-0-8c01a55d8f6a@kernel.org>
In-Reply-To: <20240215-upstream-net-20240215-misc-fixes-v1-0-8c01a55d8f6a@kernel.org>
To: mptcp@lists.linux.dev, Mat Martineau <martineau@kernel.org>, 
 Geliang Tang <geliang@kernel.org>, "David S. Miller" <davem@davemloft.net>, 
 Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, 
 Paolo Abeni <pabeni@redhat.com>, Davide Caratti <dcaratti@redhat.com>, 
 Shuah Khan <shuah@kernel.org>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, 
 linux-kselftest@vger.kernel.org, 
 "Matthieu Baerts (NGI0)" <matttbe@kernel.org>, stable@vger.kernel.org

From: Paolo Abeni <pabeni@redhat.com>

Similar to the previous patch, address the data race on
remote_id, adding the suitable ONCE annotations.

Fixes: bedee0b56113 ("mptcp: address lookup improvements")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm_netlink.c | 8 ++++----
 net/mptcp/subflow.c    | 6 +++---
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 912e25077437..ed6983af1ab2 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -443,7 +443,7 @@ static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk,
 		mptcp_for_each_subflow(msk, subflow) {
 			ssk = mptcp_subflow_tcp_sock(subflow);
 			remote_address((struct sock_common *)ssk, &addrs[i]);
-			addrs[i].id = subflow->remote_id;
+			addrs[i].id = READ_ONCE(subflow->remote_id);
 			if (deny_id0 && !addrs[i].id)
 				continue;
 
@@ -799,18 +799,18 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
 
 		mptcp_for_each_subflow_safe(msk, subflow, tmp) {
 			struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+			u8 remote_id = READ_ONCE(subflow->remote_id);
 			int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
 			u8 id = subflow_get_local_id(subflow);
 
-			if (rm_type == MPTCP_MIB_RMADDR && subflow->remote_id != rm_id)
+			if (rm_type == MPTCP_MIB_RMADDR && remote_id != rm_id)
 				continue;
 			if (rm_type == MPTCP_MIB_RMSUBFLOW && !mptcp_local_id_match(msk, id, rm_id))
 				continue;
 
 			pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u",
 				 rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
-				 i, rm_id, id, subflow->remote_id,
-				 msk->mpc_endpoint_id);
+				 i, rm_id, id, remote_id, msk->mpc_endpoint_id);
 			spin_unlock_bh(&msk->pm.lock);
 			mptcp_subflow_shutdown(sk, ssk, how);
 
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 015184bbf06c..71ba86246ff8 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -535,7 +535,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 		subflow->backup = mp_opt.backup;
 		subflow->thmac = mp_opt.thmac;
 		subflow->remote_nonce = mp_opt.nonce;
-		subflow->remote_id = mp_opt.join_id;
+		WRITE_ONCE(subflow->remote_id, mp_opt.join_id);
 		pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u backup=%d",
 			 subflow, subflow->thmac, subflow->remote_nonce,
 			 subflow->backup);
@@ -1567,7 +1567,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
 	pr_debug("msk=%p remote_token=%u local_id=%d remote_id=%d", msk,
 		 remote_token, local_id, remote_id);
 	subflow->remote_token = remote_token;
-	subflow->remote_id = remote_id;
+	WRITE_ONCE(subflow->remote_id, remote_id);
 	subflow->request_join = 1;
 	subflow->request_bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP);
 	subflow->subflow_id = msk->subflow_id++;
@@ -1974,7 +1974,7 @@ static void subflow_ulp_clone(const struct request_sock *req,
 		new_ctx->fully_established = 1;
 		new_ctx->remote_key_valid = 1;
 		new_ctx->backup = subflow_req->backup;
-		new_ctx->remote_id = subflow_req->remote_id;
+		WRITE_ONCE(new_ctx->remote_id, subflow_req->remote_id);
 		new_ctx->token = subflow_req->token;
 		new_ctx->thmac = subflow_req->thmac;
 

-- 
2.43.0