From patchwork Mon Dec 19 17:33:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 13076924 X-Patchwork-Delegate: paul@paul-moore.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 139E8C4167B for ; Mon, 19 Dec 2022 17:35:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232231AbiLSRe7 (ORCPT ); Mon, 19 Dec 2022 12:34:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232243AbiLSRe4 (ORCPT ); Mon, 19 Dec 2022 12:34:56 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79C1112AAA for ; Mon, 19 Dec 2022 09:34:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671471251; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Mge2WhqWFyM9HhE8E4llCSfJEuyu5fUhFFg1FKTv2b0=; b=Xsaf6XEdWD688xboZ5B4j3QBg9VzAlaXyKnYQDIsNdJetGOSyJNsfY8h0AUmYFujNFlfgQ AMmrgW6NAYJjgU3+odCEh5FfuK2c/m4Lp1WhGfjtoQtoKD8Tf9AEEsv1WFt+CoDMScEtaf RTz9juhEoslv4B+pb86pvFXxGLuI8fM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-590-RwNk93g1NoyypRfJLiLUAg-1; Mon, 19 Dec 2022 12:34:06 -0500 X-MC-Unique: RwNk93g1NoyypRfJLiLUAg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id EA3251802D50; Mon, 19 Dec 2022 17:34:05 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.39.193.37]) by smtp.corp.redhat.com (Postfix) with ESMTP id E4D5D2166B26; Mon, 19 Dec 2022 17:34:04 +0000 (UTC) From: Paolo Abeni To: linux-security-module@vger.kernel.org Cc: Paul Moore , selinux@vger.kernel.org, mptcp@lists.linux.dev Subject: [PATCH v2 2/2] selinux: Implement mptcp_add_subflow hook Date: Mon, 19 Dec 2022 18:33:49 +0100 Message-Id: <3074022fdca04676443a9c74f57328eb729f150e.1671469167.git.pabeni@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org Newly added subflows should inherit the associated label from the current process context, regarless of the sk_kern_sock flag value. This patch implements the above resetting the subflow sid, deleting the existing subflow label, if any, and then re-creating a new one. The new helper reuses the selinux_netlbl_sk_security_free() function, and it can end-up being called multiple times with the same argument; we additionally need to make it idempotent. Signed-off-by: Paolo Abeni --- v1 -> v2: - fix build issue with !CONFIG_NETLABEL --- security/selinux/hooks.c | 27 +++++++++++++++++++++++++++ security/selinux/netlabel.c | 4 +++- 2 files changed, 30 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 3c5be76a9199..f785600b666a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5476,6 +5476,32 @@ static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk selinux_netlbl_sctp_sk_clone(sk, newsk); } +static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + struct sk_security_struct *ssksec = ssk->sk_security; + u16 sclass; + u32 sid; + int err; + + /* create the sid using the current cred, regardless of the ssk kern + * flag + */ + sclass = socket_type_to_security_class(ssk->sk_family, ssk->sk_type, + ssk->sk_protocol); + err = socket_sockcreate_sid(tsec, sclass, &sid); + if (err) + return err; + + ssksec->sid = sid; + + /* replace the existing subflow label deleting the existing one + * and re-recrating a new label using the current context + */ + selinux_netlbl_sk_security_free(ssksec); + return selinux_netlbl_socket_post_create(ssk, ssk->sk_family); +} + static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb, struct request_sock *req) { @@ -7216,6 +7242,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone), LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect), LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established), + LSM_HOOK_INIT(mptcp_add_subflow, selinux_mptcp_add_subflow), LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request), LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone), LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established), diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 1321f15799e2..8e0080b8a8ef 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -155,8 +155,10 @@ void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error, int gateway) */ void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec) { - if (sksec->nlbl_secattr != NULL) + if (sksec->nlbl_secattr != NULL) { netlbl_secattr_free(sksec->nlbl_secattr); + sksec->nlbl_secattr = NULL; + } } /**