From mboxrd@z Thu Jan 1 00:00:00 1970 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 D98CD13B2BA; Tue, 27 Feb 2024 13:55:40 +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=1709042140; cv=none; b=srrVQqRpkofRXKdH7AK5gsCbsVq6tjAH3wWiE5s69a6PiRph4/zEtqe8PafU0VKZv/+CS5rx8KKx2aGft4Khww4kgdqaVYGTnvl19spW0e3DymFtOVl5mGFNvHCPwjLr9TUMSAd3Tejp6IN61PdmtcZToNJP6kiZj0ZHb6jWsCQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709042140; c=relaxed/simple; bh=kJyUr1hYQhSShzwmSnmK0e6hVApaSvOh4/iO2G1OdB0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T/wgvGyoXawwwSHO+fBKVn3Dj/XFd5RmDzwZC+p8KvBtl1mT03kgw4/NAQ0UypOeIW/HE5FElmCYTmkKf7QQnT0hieVhXF5o4tZMA+qgm1blgEGG3qZqcQsukQBU2DYP7vJ2FU7I7m/KiIghtMU+9BM2J6vmuqykvEdoYqN/RoY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=D5DFXhiS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="D5DFXhiS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 685E1C433C7; Tue, 27 Feb 2024 13:55:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709042140; bh=kJyUr1hYQhSShzwmSnmK0e6hVApaSvOh4/iO2G1OdB0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D5DFXhiSgFlIok8OurT6VijxK1tipYEbP7XOqnkETkgkufEi+Jn31VK/7gb+O8i52 V0XGzi3p10mld4ECsEv4eGqVbF25r10vyJ3+obYW3RyuLwZHN+/HRhGsAGyG1JQSGN HdLzmfhBahfL3tFxczmFJfwct2P4y9znr9XNfIu8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Abeni , Mat Martineau , "Matthieu Baerts (NGI0)" , "David S. Miller" Subject: [PATCH 6.6 194/299] mptcp: fix data races on local_id Date: Tue, 27 Feb 2024 14:25:05 +0100 Message-ID: <20240227131632.061885168@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240227131625.847743063@linuxfoundation.org> References: <20240227131625.847743063@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni commit a7cfe776637004a4c938fde78be4bd608c32c3ef upstream. 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) Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/mptcp/diag.c | 2 +- net/mptcp/pm_netlink.c | 6 +++--- net/mptcp/protocol.c | 2 +- net/mptcp/protocol.h | 15 ++++++++++++--- net/mptcp/subflow.c | 9 +++++---- 5 files changed, 22 insertions(+), 12 deletions(-) --- a/net/mptcp/diag.c +++ b/net/mptcp/diag.c @@ -65,7 +65,7 @@ static int subflow_get_info(struct sock 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 = -EMSGSIZE; goto nla_failure; } --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -800,7 +800,7 @@ static void mptcp_pm_nl_rm_addr_or_subfl mptcp_for_each_subflow_safe(msk, subflow, tmp) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); int how = RCV_SHUTDOWN | SEND_SHUTDOWN; - u8 id = subflow->local_id; + u8 id = subflow_get_local_id(subflow); if (rm_type == MPTCP_MIB_RMADDR && subflow->remote_id != rm_id) continue; @@ -809,7 +809,7 @@ static void mptcp_pm_nl_rm_addr_or_subfl 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, 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); @@ -2005,7 +2005,7 @@ static int mptcp_event_add_subflow(struc if (WARN_ON_ONCE(!sf)) return -EINVAL; - 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; if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id)) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -99,7 +99,7 @@ static int __mptcp_socket_create(struct subflow->subflow_id = msk->subflow_id++; /* This is the first subflow, always with id 0 */ - subflow->local_id_valid = 1; + WRITE_ONCE(subflow->local_id, 0); mptcp_sock_graft(msk->first, sk->sk_socket); iput(SOCK_INODE(ssock)); --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -493,10 +493,9 @@ 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; enum mptcp_data_avail data_avail; bool scheduled; u32 remote_nonce; @@ -507,7 +506,7 @@ 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; @@ -558,6 +557,7 @@ mptcp_subflow_ctx_reset(struct mptcp_sub { memset(&subflow->reset, 0, sizeof(subflow->reset)); subflow->request_mptcp = 1; + WRITE_ONCE(subflow->local_id, -1); } static inline u64 @@ -1008,6 +1008,15 @@ int mptcp_pm_get_local_id(struct mptcp_s int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc); int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc); +static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflow) +{ + int local_id = 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, --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -577,8 +577,8 @@ do_reset: static void subflow_set_local_id(struct mptcp_subflow_context *subflow, int local_id) { - subflow->local_id = local_id; - subflow->local_id_valid = 1; + WARN_ON_ONCE(local_id < 0 || local_id > 255); + WRITE_ONCE(subflow->local_id, local_id); } static int subflow_chk_local_id(struct sock *sk) @@ -587,7 +587,7 @@ static int subflow_chk_local_id(struct s struct mptcp_sock *msk = mptcp_sk(subflow->conn); int err; - if (likely(subflow->local_id_valid)) + if (likely(subflow->local_id >= 0)) return 0; err = mptcp_pm_get_local_id(msk, (struct sock_common *)sk); @@ -1723,6 +1723,7 @@ static struct mptcp_subflow_context *sub pr_debug("subflow=%p", ctx); ctx->tcp_sock = sk; + WRITE_ONCE(ctx->local_id, -1); return ctx; } @@ -1958,7 +1959,7 @@ static void subflow_ulp_clone(const stru new_ctx->idsn = subflow_req->idsn; /* this is the first subflow, id is always 0 */ - new_ctx->local_id_valid = 1; + subflow_set_local_id(new_ctx, 0); } else if (subflow_req->mp_join) { new_ctx->ssn_offset = subflow_req->ssn_offset; new_ctx->mp_join = 1;