From nobody Mon Feb 9 10:58:24 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F0A613AA29; Thu, 15 Feb 2024 18:25:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708021551; cv=none; b=KuGeM0+4BfZ/v3gJdIt2oHI/Gve7JUjwbYHlGaN08z0vEz+9U7JgfreTSni0ZQfIZ97ieC51/GEa1/QW9gYgoyRlqP1b+CNIEXO4wckRBGHnOllcud/iE77W1ABSlHjET2KDxEwED3+dZ3HYvXPfPtIYVDE2y0+j/7+6aLh8m4A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708021551; c=relaxed/simple; bh=OHtghzBpai6zL2VBEImfx8tJSSEJN0SuOVGpf6g87y8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=e1HmhzD+jFdMpH3fIUcednxKn9ndSuAmxEjNAeM1yO9cl8Ee6x+MuJANx/uQCnysv5sjKVA5cOCrVkRI1Z7CaFCxfgrRWPYZ3+7/HB1Uc5Me/n8fQbOw6pgUtnK1AYRIqRDZ3p1OC6nUw604VrBdUdBTt+tyT2C3w7m3uSJdRRU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d8nXVTuH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="d8nXVTuH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CD19C433C7; Thu, 15 Feb 2024 18:25:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708021550; bh=OHtghzBpai6zL2VBEImfx8tJSSEJN0SuOVGpf6g87y8=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=d8nXVTuHEcmJc0wuMqrJT9PEUe0JeYBdXolJvpe/onsVgYTiZXl7OdcTKZW8ifJbW 2tVN3tUxqfFl0xsnub+tdaR5LqAx/rUwEJ1NFtLsYYPfUJZrJRpWSpt/iJHcj9d9yG laoHgmL8BF5JddBolcPRKkuFIjayD+KYnL6xwf6iSqZZ5AMiHGDn4AgfevJPGyL3Lp dHjrTUuE+p8eTSWyWGAsOLq6rxwNErIFghDz++rt3Mi4RGwKRIqlrtKE1M9WbJ9Bzr mve1wBi6NS0s4wPo+90KMvskpssw4+UAgZg8MOTBLaa/QtPHPUCp/DRzS6Wpic/Vq8 +E6zjd6ljI2Ag== From: "Matthieu Baerts (NGI0)" Date: Thu, 15 Feb 2024 19:25:31 +0100 Subject: [PATCH net 04/13] mptcp: fix data races on local_id Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20240215-upstream-net-20240215-misc-fixes-v1-4-8c01a55d8f6a@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 , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Davide Caratti , Shuah Khan Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, "Matthieu Baerts (NGI0)" , stable@vger.kernel.org X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=7176; i=matttbe@kernel.org; h=from:subject:message-id; bh=quJW5M/2G3Dvm2MZlUXMbs6cwclKCNyj5WPf/FoK3+8=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBlzlccY2QNT2m5csL7F4Hv6Z6DwUiZ5TLSiT8mE 7GCwk7wb8CJAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZc5XHAAKCRD2t4JPQmmg c1yPEADXvkRaowUNS1xsIgh5+vrKxrhXCwkih+1XPBw/1XTjLXcxo+i8/Pr0hJTxoc5kYCAH3g+ NXrnZmhTa6QhySQc05+jJKKDi7Eqjuz1uYMa3LzoklvX18qAmS7Vt8HU8qZUMgSCYwXmYj6Yto2 Mcee9p6oycYOaF/LzOc8K136wNoUp7pels/MsgEwnaZ7EjqKJa9J0ZU2uaOojBf2OqmLPA19sgu 4j2LfMgoOeVCWwdnGofrwxRqfdCRjVQpConMrvHnCXgM1EpvCdbZXEUZL/rQL4jaDcqNh13FpCj ubQDTtReTKiKu6+e9r+39OQ4zHdsuscyFSh/2b0FN4cFMkicTPQ51mXfQfpBnuoiJ7JxmrCkyIw VUgoZRTrkbCJHlvoMxaOYSELfOHqCyTM2+G5/nzllThDhgB4imjlC5OZtoNF5evC/VowozMnMtb dS6EuSnBnHKfKGhWuX2qTxyFCFhaNmK+iNFABYt6A7qiYjANaeVSm3sMExpi97JrYDDenJosTw5 4FEN5wi2POdV+9kgzohs2AFg2NW9Sr4GXUheNlK+AGUeFo8hDmseGb67EPfXCpz0d3+d4hHbOlq 0nPN+WyDyV8Ky3+5nxdtTcQsZYbuuQ/NcmnGRPPikqSSwhrV5W7oQBw80OmbBeevUJO7wNZJn2F aH0AMEViEYUJkSg== X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 From: Paolo Abeni The local address id is accessed lockless by the NL PM, add all the required ONCE annotation. There is a caveat: the local id can be initialized late in the subflow life-cycle, and its validity is controlled by the local_id_valid flag. Remove such flag and encode the validity in the local_id field itself with negative value before initialization. That allows accessing the field consistently with a single read operation. Fixes: 0ee4261a3681 ("mptcp: implement mptcp_pm_remove_subflow") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/diag.c | 2 +- net/mptcp/pm_netlink.c | 6 +++--- net/mptcp/pm_userspace.c | 2 +- net/mptcp/protocol.c | 2 +- net/mptcp/protocol.h | 15 ++++++++++++--- net/mptcp/subflow.c | 9 +++++---- 6 files changed, 23 insertions(+), 13 deletions(-) diff --git a/net/mptcp/diag.c b/net/mptcp/diag.c index e57c5f47f035..6ff6f14674aa 100644 --- a/net/mptcp/diag.c +++ b/net/mptcp/diag.c @@ -65,7 +65,7 @@ static int subflow_get_info(struct sock *sk, struct sk_bu= ff *skb) sf->map_data_len) || nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_FLAGS, flags) || nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_REM, sf->remote_id) || - nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_LOC, sf->local_id)) { + nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_LOC, subflow_get_local_id(sf)))= { err =3D -EMSGSIZE; goto nla_failure; } diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index a24c9128dee9..912e25077437 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -800,7 +800,7 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp= _sock *msk, mptcp_for_each_subflow_safe(msk, subflow, tmp) { struct sock *ssk =3D mptcp_subflow_tcp_sock(subflow); int how =3D RCV_SHUTDOWN | SEND_SHUTDOWN; - u8 id =3D subflow->local_id; + u8 id =3D subflow_get_local_id(subflow); =20 if (rm_type =3D=3D MPTCP_MIB_RMADDR && subflow->remote_id !=3D rm_id) continue; @@ -809,7 +809,7 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp= _sock *msk, =20 pr_debug(" -> %s rm_list_ids[%d]=3D%u local_id=3D%u remote_id=3D%u mpc_= id=3D%u", rm_type =3D=3D MPTCP_MIB_RMADDR ? "address" : "subflow", - i, rm_id, subflow->local_id, subflow->remote_id, + i, rm_id, id, subflow->remote_id, msk->mpc_endpoint_id); spin_unlock_bh(&msk->pm.lock); mptcp_subflow_shutdown(sk, ssk, how); @@ -1994,7 +1994,7 @@ static int mptcp_event_add_subflow(struct sk_buff *sk= b, const struct sock *ssk) if (WARN_ON_ONCE(!sf)) return -EINVAL; =20 - if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, sf->local_id)) + if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, subflow_get_local_id(sf))) return -EMSGSIZE; =20 if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id)) diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index e582b3b2d174..d396a5973429 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -234,7 +234,7 @@ static int mptcp_userspace_pm_remove_id_zero_address(st= ruct mptcp_sock *msk, =20 lock_sock(sk); mptcp_for_each_subflow(msk, subflow) { - if (subflow->local_id =3D=3D 0) { + if (READ_ONCE(subflow->local_id) =3D=3D 0) { has_id_0 =3D true; break; } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8ef2927ebca2..948606a537da 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -85,7 +85,7 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) subflow->subflow_id =3D msk->subflow_id++; =20 /* This is the first subflow, always with id 0 */ - subflow->local_id_valid =3D 1; + WRITE_ONCE(subflow->local_id, 0); mptcp_sock_graft(msk->first, sk->sk_socket); iput(SOCK_INODE(ssock)); =20 diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index ed50f2015dc3..631a7f445f34 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -491,10 +491,9 @@ struct mptcp_subflow_context { remote_key_valid : 1, /* received the peer key from */ disposable : 1, /* ctx can be free at ulp release time */ stale : 1, /* unable to snd/rcv data, do not use for xmit */ - local_id_valid : 1, /* local_id is correctly initialized */ valid_csum_seen : 1, /* at least one csum validated */ is_mptfo : 1, /* subflow is doing TFO */ - __unused : 9; + __unused : 10; bool data_avail; bool scheduled; u32 remote_nonce; @@ -505,7 +504,7 @@ struct mptcp_subflow_context { u8 hmac[MPTCPOPT_HMAC_LEN]; /* MPJ subflow only */ u64 iasn; /* initial ack sequence number, MPC subflows only */ }; - u8 local_id; + s16 local_id; /* if negative not initialized yet */ u8 remote_id; u8 reset_seen:1; u8 reset_transient:1; @@ -556,6 +555,7 @@ mptcp_subflow_ctx_reset(struct mptcp_subflow_context *s= ubflow) { memset(&subflow->reset, 0, sizeof(subflow->reset)); subflow->request_mptcp =3D 1; + WRITE_ONCE(subflow->local_id, -1); } =20 static inline u64 @@ -1022,6 +1022,15 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, st= ruct sock_common *skc); int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_inf= o *skc); int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_a= ddr_info *skc); =20 +static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *= subflow) +{ + int local_id =3D READ_ONCE(subflow->local_id); + + if (local_id < 0) + return 0; + return local_id; +} + void __init mptcp_pm_nl_init(void); void mptcp_pm_nl_work(struct mptcp_sock *msk); void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index c34ecadee120..015184bbf06c 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -577,8 +577,8 @@ static void subflow_finish_connect(struct sock *sk, con= st struct sk_buff *skb) =20 static void subflow_set_local_id(struct mptcp_subflow_context *subflow, in= t local_id) { - subflow->local_id =3D local_id; - subflow->local_id_valid =3D 1; + WARN_ON_ONCE(local_id < 0 || local_id > 255); + WRITE_ONCE(subflow->local_id, local_id); } =20 static int subflow_chk_local_id(struct sock *sk) @@ -587,7 +587,7 @@ static int subflow_chk_local_id(struct sock *sk) struct mptcp_sock *msk =3D mptcp_sk(subflow->conn); int err; =20 - if (likely(subflow->local_id_valid)) + if (likely(subflow->local_id >=3D 0)) return 0; =20 err =3D mptcp_pm_get_local_id(msk, (struct sock_common *)sk); @@ -1731,6 +1731,7 @@ static struct mptcp_subflow_context *subflow_create_c= tx(struct sock *sk, pr_debug("subflow=3D%p", ctx); =20 ctx->tcp_sock =3D sk; + WRITE_ONCE(ctx->local_id, -1); =20 return ctx; } @@ -1966,7 +1967,7 @@ static void subflow_ulp_clone(const struct request_so= ck *req, new_ctx->idsn =3D subflow_req->idsn; =20 /* this is the first subflow, id is always 0 */ - new_ctx->local_id_valid =3D 1; + subflow_set_local_id(new_ctx, 0); } else if (subflow_req->mp_join) { new_ctx->ssn_offset =3D subflow_req->ssn_offset; new_ctx->mp_join =3D 1; --=20 2.43.0