From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C1E0C433E9 for ; Tue, 9 Mar 2021 15:06:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C9F86525F for ; Tue, 9 Mar 2021 15:06:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231445AbhCIPF3 (ORCPT ); Tue, 9 Mar 2021 10:05:29 -0500 Received: from sonic317-38.consmr.mail.ne1.yahoo.com ([66.163.184.49]:46070 "EHLO sonic317-38.consmr.mail.ne1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231932AbhCIPFH (ORCPT ); Tue, 9 Mar 2021 10:05:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1615302306; bh=omFPyEjnY2cGDGLKwfF2DECd7JyX0trPj8ccTe5YsPc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject:Reply-To; b=d940G/CQrzevZEsO9LJe2Efka9ztt0OF7P1owyVTjl99NqpB6OLzPtuSjrPzp8mQxJSDYhb/5Sp4M7hEggHkH27hA2TL8zH/sPmRCTXU68qh7zWiUaXnNtItuN7oohbnGhRaq05I9ONCn9o8B8LCj83nQK1PEv7dVTVR0uvT/K5zNglDymVyYpKxgGZplIx3kvbj9HnQcADfD+mrrmFkt6UuKJk4YONbrtl73F8RD1G4QiCBC5p9qCzDzC82ykj16BwoQVhswGVHQuUTCDEgMhwHJBh/G7C44wl5mPqAqeTAb9IGyit0dL1qLeH2hOQIQ6PvNz+XpxjCE4jUSRX3ww== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1615302306; bh=3WYZ49h+ubXzSBzg2RJxbOCE6ty+0cjSdrG2U72yPBd=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=FCwd5LSGdiVw97kGJm306TW0Ak+ePu5ByKE/qJ9YOWC9V36iY78n2H3zFrgS8Qnz6CpmyRd7B2qAdg0XJZ/hya4VxNDTX9N/jqWjCo+1Gjo2xdo8TvIjyZCL6AZOLWya/m8PDIxZYveCbbrIbsmHGtmifG8FbCnWHjVyU5eW+LE60+I9XcpEP5Q3+D98axMF9g1pOwGw5F6Zwgf6PNJ4Biuud18vtIa+ncsQh+DEpW3UUcX9JN6znpONT8XnM46oWuTfAjLZ3aXMlqD3myojTF1bVAU2wz6SzacwPNy3bxw/49PFH/x0eRx5BPfQ7oDEo/9ARaxLV0K/uZXnLokz1w== X-YMail-OSG: RRWc8XIVM1n065f1kMl2RVYJ1LtQOlxQkTH.hTmd3VWdJjznHdVakNP_xBMpOLc wdnihRfHnait4F2MIWqRHYLi_dOrFgampxDDRpq3LiqQRaYbv2_S8Onzg99XVPfVEHzBxlqj0pcv B2SAZAyzPmDSFwI0ij0f2eqVXPBKrndbawcYjOzemS3JlkgFYysAdfMN1GfKNWeYLmRT0e5MxIlY _moODuRTr2IWHINdUkv182OkUl4Zzs3a8m5Y1VE32u.OVE7ueA9ASN3PRMclM0WC6AQ7qViOvAl2 Q_M8DxX7ut25hzVg860tqUnQ6iVR_3orPk_gzZ5Jxj0TyNgd7NjKTGqkQVr8nPAqO0zgxLBc__TD g.uEODRBXOF3B2Q_AJSSBf6UNqtT0pISsHgS5IWdhIiYboa6HjdfiVMaNKadFeO0PMfuFG0U7Chz VxwoML9.X_EHEhrz0wTi_9v0i2Hx8TorgjvUhCSV6Al4VXBhR2ttTzNdA48ogxhZ_XFKMzhM9O6g Jr0pO833BlscH438nMkYKbe7.QRF4P1uSAkaXj7wAlYLsfVvAZI7Gd8rawJm4CiLJD4U0qBSRDzd pQ58nPIXlKRG1nbJrC9_OpuOMQIi01NWYu2z0u7VKQxX3vM.g066bMej0B_sJ2I5RCIpo_R810t3 iy10CPHt6YfIV4eEnOfQadSXNWm9iT73RX1FTVBYT6Dh_NF1QoZdflLqbBkhMnji_wV9EZo6DqAC LpvRj4i0H0jqNT2j7XNrmxgqTU21Y4HfCFnAKYtoWR7pxpytEroWper.SloWwMd2IeJfMGLWDjjY 8c.A0vt6aESx9p4vhBLf6IvvXvsE4wGmZJ9vMSzkgKjlcbzuT5uhWHgW15Xk8r4IwxZgdhNEdDBr QbBFvJdZD3UT0M2aDL_2vNY1WeZrg4ZHcvIx_jI3B3ivpS_PiJWusZMSQDTHmN1bfBWyp8DAhPPD Ig1bot6RpfNEOI3sRNpr.ZlSefyd3NbjPcLegU5VGFB_0RUe3xWzOSMSxwGKbPRPoPB8ZHVNlrtX QKFrAU04sNLM5AmIhSfH3kROz.nj_7w6Ki_MsV45cJ8WfSeQtb.9bgPix_c59LlmT2jdrsqlD6FD sPKK6.PhKppI7AEBrvmS.WDInL7RoEJYvDlSxz7bQAFmavPHpziTtf3ahfDm9zpiBqPv1cyPSKC_ 3KQNKsx800DRrqw_KscYcZL6jyVXbBOFyVa.sXeGrSx7TlX4SwB.9PafylXpZ8YTDnC_ZfaYoNef i7zHbxo.M9xmLFSwsiaPm_5JwMX_6uLlGWyL2swMGeNX6joFc0nLHJVLkOXfSOVZcajrZaniWBko f2JV6SIRinIMz6.ZT0Rn_A.Rrwpvrnmyn1u13lJIk8TKroexGUdYdfUZ1BhXhs_bN672BofeiWId ALmJ9SYnd3bb.5B.y8UnCT9_R_vcfNxsBuFzqkV8ea5vi2nXepqcDoJciRPRzSZ5MAs19QVve2Hj p41KkNA34poJR6qMtP3bEK08gSVNCAfSzfLszXb4L8K91nUX5m7qrzJCahIj1VWG1NpAya.s91kI VIsaF2LiuuRPhbzUEdF811wzkwe1R9T_xsiT7YLn2ImfDKOjiK6oDjkqOusH1p7DSDr8YBX7jNfQ .81Wdfbp8HT5GJaP9sIcablrzRnaStrEQ7zoMP2ZCn78DcBM_WrUKoHg_7wmPuSsqnOwjwHDTlkZ VoqmDxaeUP28hwloq5FWGIFVUtz7VJhr1EqCZ6qUgIoDgBj3IYtbA5wjOn_.RfcGT2nTzHCcTAup ohhNz5NykSWCFsAZq76wUqPMeL.zt6NvXHUyG_QqNsHlgjIH9d24Re1fXPQXUKuqHHu4c6oQA17r n_O.EtCJoP6r35PDatBEO9XmWQaqQwuCCC99M6UjJvvHKdoiR_0YqiOzCDw9JAUz9c75B1cos.Ju 62p9pzaRf3tAPDlGuvsxTR_uyUqDNFjleD7oinKOe8k0LiWRgYQRytagxVG_6Keta2IUSGUNmVCC JLn9ZQ5A3GmBYkFckdtdq.4yiBcYd0e5rrQ9inFycq2I3CTJaXZiXAyuPIb8BIyoUmDd3L62p0R_ n30z3K.MVooKTHbi2iBWZxAKQlvSXxix1iCmi7LdydYWmqPum9NraWs45H6yKvAP_ZVhYtn0_U5d vbROt5Z7Kg89xLKz1ty0JglpEYkVIiVxXm3PliOk08PWHNRaHbiuAa6s80VzZwfQ9LFdoDJL3cXn 9E0pE2k8cmLt3jNKNCPZbAmEn4j4FbIbN8uvUhq5h5mugyFnWAxnn2zc9fWPG87GGwC43DUJ7IFj Ut8IU.Y95Sz8311ETnlNnEItdEyt5OYE1WxtRYakdQMVQAscHRJiCWYB5IfXos9XzPRp4QanLuGa SGNEoxnePNaLUKG4rP4mtIM.ayFuaeo9YDu1s5y6ja0uN1wa0ViddbqiXlSoneQ9KV0i20ESY18r ZLNSrJe7N68qsiCioRoLRq9_0styAoX1j83FS3aBwGO5tAhaPyqEqPyggB8fY1Mvzg6abTLWv2Jv EJUUgIe2mzcNB42jN4.Eh9oBDaKyigPoyLN7UGDSn75DBG9tMooS1IT7z_DJNDRCb3eVhV88Kwec gMMyA9DY0Qv.mzf.qFYPSilAIqwGyzV.TwvmnUrAjqYZ6kqN9fWqSk6JI50cxZXu9MbsObbWQbNl RqHY0vYvJATSy_PZs.KRqM41ZcnSscue6m5Byra7BPXrXV3kyrAel6glMzh.6U88ngQsRcCa6IRY tloo3jI1K6T6Omi2HsNbZf6R5yZRi6Ut4v.IvhnpGGYphab3Zbt2.s2baC7WzIiiemr9Kka7iGnE 1faaWL9bR5_6xxd6GRfIlKIfMjLlIyplmSq0RejPx7RJl4xAoqQiNmWFvb573CUa6F.T5CeI2l9u oyhewFIZ7Z2Bue33L3F4T9352tXOM5xNQC3Bgj6RnXNjLNHhTMGsK20RHIKreLuMnqGyGfOKq8Xz 5iA5Wk02ZCmp9G5Kk9X8yLUYoThIODFkNC3Ky1hq9ZL6hNEb.lvv4tTEcNnC1Fy6FoTFFgHezUH3 I2RrzekaIcx4GIp1fTIENejW4BimF2u_LKocNfBJeWWDyhNzDfOs8tgc11JfZ X-Sonic-MF: Received: from sonic.gate.mail.ne1.yahoo.com by sonic317.consmr.mail.ne1.yahoo.com with HTTP; Tue, 9 Mar 2021 15:05:06 +0000 Received: by smtp425.mail.ne1.yahoo.com (VZM Hermes SMTP Server) with ESMTPA ID 8035a072f5ee31803d67cfe7edfa7010; Tue, 09 Mar 2021 15:05:04 +0000 (UTC) From: Casey Schaufler To: casey.schaufler@intel.com, jmorris@namei.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Cc: casey@schaufler-ca.com, linux-audit@redhat.com, keescook@chromium.org, john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp, paul@paul-moore.com, sds@tycho.nsa.gov, linux-kernel@vger.kernel.org Subject: [PATCH v25 20/25] LSM: Verify LSM display sanity in binder Date: Tue, 9 Mar 2021 06:42:38 -0800 Message-Id: <20210309144243.12519-21-casey@schaufler-ca.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210309144243.12519-1-casey@schaufler-ca.com> References: <20210309144243.12519-1-casey@schaufler-ca.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Verify that the tasks on the ends of a binder transaction use the same "display" security module. This prevents confusion of security "contexts". Reviewed-by: Kees Cook Reviewed-by: John Johansen Acked-by: Stephen Smalley Acked-by: Paul Moore Signed-off-by: Casey Schaufler --- security/security.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/security/security.c b/security/security.c index b88f916e0698..5d3dad5f800f 100644 --- a/security/security.c +++ b/security/security.c @@ -834,9 +834,38 @@ int security_binder_set_context_mgr(struct task_struct *mgr) return call_int_hook(binder_set_context_mgr, 0, mgr); } +/** + * security_binder_transaction - Binder driver transaction check + * @from: source of the transaction + * @to: destination of the transaction + * + * Verify that the tasks have the same LSM "display", then + * call the security module hooks. + * + * Returns -EINVAL if the displays don't match, or the + * result of the security module checks. + */ int security_binder_transaction(struct task_struct *from, struct task_struct *to) { + int from_ilsm = lsm_task_ilsm(from); + int to_ilsm = lsm_task_ilsm(to); + + /* + * If the ilsm is LSMBLOB_INVALID the first module that has + * an entry is used. This will be in the 0 slot. + * + * This is currently only required if the server has requested + * peer contexts, but it would be unwieldly to have too much of + * the binder driver detail here. + */ + if (from_ilsm == LSMBLOB_INVALID) + from_ilsm = 0; + if (to_ilsm == LSMBLOB_INVALID) + to_ilsm = 0; + if (from_ilsm != to_ilsm) + return -EINVAL; + return call_int_hook(binder_transaction, 0, from, to); } -- 2.29.2 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C332C433E6 for ; Tue, 9 Mar 2021 15:05:25 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D238A65243 for ; Tue, 9 Mar 2021 15:05:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D238A65243 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=schaufler-ca.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=linux-audit-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-63-lhnbza8RP16pR5I2r_fJ6w-1; Tue, 09 Mar 2021 10:05:21 -0500 X-MC-Unique: lhnbza8RP16pR5I2r_fJ6w-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id ECC381005D4C; Tue, 9 Mar 2021 15:05:17 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C029819C59; Tue, 9 Mar 2021 15:05:17 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 5FC195002F; Tue, 9 Mar 2021 15:05:17 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 129F5Gk8022363 for ; Tue, 9 Mar 2021 10:05:16 -0500 Received: by smtp.corp.redhat.com (Postfix) id 01161112CA23; Tue, 9 Mar 2021 15:05:16 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast04.extmail.prod.ext.rdu2.redhat.com [10.11.55.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F089B112CA21 for ; Tue, 9 Mar 2021 15:05:09 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 43A61100B389 for ; Tue, 9 Mar 2021 15:05:09 +0000 (UTC) Received: from sonic317-38.consmr.mail.ne1.yahoo.com (sonic317-38.consmr.mail.ne1.yahoo.com [66.163.184.49]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-474-ZgXfPTFfMhqaonjHh2SU8Q-1; Tue, 09 Mar 2021 10:05:06 -0500 X-MC-Unique: ZgXfPTFfMhqaonjHh2SU8Q-1 X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1615302306; bh=3WYZ49h+ubXzSBzg2RJxbOCE6ty+0cjSdrG2U72yPBd=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=FCwd5LSGdiVw97kGJm306TW0Ak+ePu5ByKE/qJ9YOWC9V36iY78n2H3zFrgS8Qnz6CpmyRd7B2qAdg0XJZ/hya4VxNDTX9N/jqWjCo+1Gjo2xdo8TvIjyZCL6AZOLWya/m8PDIxZYveCbbrIbsmHGtmifG8FbCnWHjVyU5eW+LE60+I9XcpEP5Q3+D98axMF9g1pOwGw5F6Zwgf6PNJ4Biuud18vtIa+ncsQh+DEpW3UUcX9JN6znpONT8XnM46oWuTfAjLZ3aXMlqD3myojTF1bVAU2wz6SzacwPNy3bxw/49PFH/x0eRx5BPfQ7oDEo/9ARaxLV0K/uZXnLokz1w== X-YMail-OSG: RRWc8XIVM1n065f1kMl2RVYJ1LtQOlxQkTH.hTmd3VWdJjznHdVakNP_xBMpOLc wdnihRfHnait4F2MIWqRHYLi_dOrFgampxDDRpq3LiqQRaYbv2_S8Onzg99XVPfVEHzBxlqj0pcv B2SAZAyzPmDSFwI0ij0f2eqVXPBKrndbawcYjOzemS3JlkgFYysAdfMN1GfKNWeYLmRT0e5MxIlY _moODuRTr2IWHINdUkv182OkUl4Zzs3a8m5Y1VE32u.OVE7ueA9ASN3PRMclM0WC6AQ7qViOvAl2 Q_M8DxX7ut25hzVg860tqUnQ6iVR_3orPk_gzZ5Jxj0TyNgd7NjKTGqkQVr8nPAqO0zgxLBc__TD g.uEODRBXOF3B2Q_AJSSBf6UNqtT0pISsHgS5IWdhIiYboa6HjdfiVMaNKadFeO0PMfuFG0U7Chz VxwoML9.X_EHEhrz0wTi_9v0i2Hx8TorgjvUhCSV6Al4VXBhR2ttTzNdA48ogxhZ_XFKMzhM9O6g Jr0pO833BlscH438nMkYKbe7.QRF4P1uSAkaXj7wAlYLsfVvAZI7Gd8rawJm4CiLJD4U0qBSRDzd pQ58nPIXlKRG1nbJrC9_OpuOMQIi01NWYu2z0u7VKQxX3vM.g066bMej0B_sJ2I5RCIpo_R810t3 iy10CPHt6YfIV4eEnOfQadSXNWm9iT73RX1FTVBYT6Dh_NF1QoZdflLqbBkhMnji_wV9EZo6DqAC LpvRj4i0H0jqNT2j7XNrmxgqTU21Y4HfCFnAKYtoWR7pxpytEroWper.SloWwMd2IeJfMGLWDjjY 8c.A0vt6aESx9p4vhBLf6IvvXvsE4wGmZJ9vMSzkgKjlcbzuT5uhWHgW15Xk8r4IwxZgdhNEdDBr QbBFvJdZD3UT0M2aDL_2vNY1WeZrg4ZHcvIx_jI3B3ivpS_PiJWusZMSQDTHmN1bfBWyp8DAhPPD Ig1bot6RpfNEOI3sRNpr.ZlSefyd3NbjPcLegU5VGFB_0RUe3xWzOSMSxwGKbPRPoPB8ZHVNlrtX QKFrAU04sNLM5AmIhSfH3kROz.nj_7w6Ki_MsV45cJ8WfSeQtb.9bgPix_c59LlmT2jdrsqlD6FD sPKK6.PhKppI7AEBrvmS.WDInL7RoEJYvDlSxz7bQAFmavPHpziTtf3ahfDm9zpiBqPv1cyPSKC_ 3KQNKsx800DRrqw_KscYcZL6jyVXbBOFyVa.sXeGrSx7TlX4SwB.9PafylXpZ8YTDnC_ZfaYoNef i7zHbxo.M9xmLFSwsiaPm_5JwMX_6uLlGWyL2swMGeNX6joFc0nLHJVLkOXfSOVZcajrZaniWBko f2JV6SIRinIMz6.ZT0Rn_A.Rrwpvrnmyn1u13lJIk8TKroexGUdYdfUZ1BhXhs_bN672BofeiWId ALmJ9SYnd3bb.5B.y8UnCT9_R_vcfNxsBuFzqkV8ea5vi2nXepqcDoJciRPRzSZ5MAs19QVve2Hj p41KkNA34poJR6qMtP3bEK08gSVNCAfSzfLszXb4L8K91nUX5m7qrzJCahIj1VWG1NpAya.s91kI VIsaF2LiuuRPhbzUEdF811wzkwe1R9T_xsiT7YLn2ImfDKOjiK6oDjkqOusH1p7DSDr8YBX7jNfQ .81Wdfbp8HT5GJaP9sIcablrzRnaStrEQ7zoMP2ZCn78DcBM_WrUKoHg_7wmPuSsqnOwjwHDTlkZ VoqmDxaeUP28hwloq5FWGIFVUtz7VJhr1EqCZ6qUgIoDgBj3IYtbA5wjOn_.RfcGT2nTzHCcTAup ohhNz5NykSWCFsAZq76wUqPMeL.zt6NvXHUyG_QqNsHlgjIH9d24Re1fXPQXUKuqHHu4c6oQA17r n_O.EtCJoP6r35PDatBEO9XmWQaqQwuCCC99M6UjJvvHKdoiR_0YqiOzCDw9JAUz9c75B1cos.Ju 62p9pzaRf3tAPDlGuvsxTR_uyUqDNFjleD7oinKOe8k0LiWRgYQRytagxVG_6Keta2IUSGUNmVCC JLn9ZQ5A3GmBYkFckdtdq.4yiBcYd0e5rrQ9inFycq2I3CTJaXZiXAyuPIb8BIyoUmDd3L62p0R_ n30z3K.MVooKTHbi2iBWZxAKQlvSXxix1iCmi7LdydYWmqPum9NraWs45H6yKvAP_ZVhYtn0_U5d vbROt5Z7Kg89xLKz1ty0JglpEYkVIiVxXm3PliOk08PWHNRaHbiuAa6s80VzZwfQ9LFdoDJL3cXn 9E0pE2k8cmLt3jNKNCPZbAmEn4j4FbIbN8uvUhq5h5mugyFnWAxnn2zc9fWPG87GGwC43DUJ7IFj Ut8IU.Y95Sz8311ETnlNnEItdEyt5OYE1WxtRYakdQMVQAscHRJiCWYB5IfXos9XzPRp4QanLuGa SGNEoxnePNaLUKG4rP4mtIM.ayFuaeo9YDu1s5y6ja0uN1wa0ViddbqiXlSoneQ9KV0i20ESY18r ZLNSrJe7N68qsiCioRoLRq9_0styAoX1j83FS3aBwGO5tAhaPyqEqPyggB8fY1Mvzg6abTLWv2Jv EJUUgIe2mzcNB42jN4.Eh9oBDaKyigPoyLN7UGDSn75DBG9tMooS1IT7z_DJNDRCb3eVhV88Kwec gMMyA9DY0Qv.mzf.qFYPSilAIqwGyzV.TwvmnUrAjqYZ6kqN9fWqSk6JI50cxZXu9MbsObbWQbNl RqHY0vYvJATSy_PZs.KRqM41ZcnSscue6m5Byra7BPXrXV3kyrAel6glMzh.6U88ngQsRcCa6IRY tloo3jI1K6T6Omi2HsNbZf6R5yZRi6Ut4v.IvhnpGGYphab3Zbt2.s2baC7WzIiiemr9Kka7iGnE 1faaWL9bR5_6xxd6GRfIlKIfMjLlIyplmSq0RejPx7RJl4xAoqQiNmWFvb573CUa6F.T5CeI2l9u oyhewFIZ7Z2Bue33L3F4T9352tXOM5xNQC3Bgj6RnXNjLNHhTMGsK20RHIKreLuMnqGyGfOKq8Xz 5iA5Wk02ZCmp9G5Kk9X8yLUYoThIODFkNC3Ky1hq9ZL6hNEb.lvv4tTEcNnC1Fy6FoTFFgHezUH3 I2RrzekaIcx4GIp1fTIENejW4BimF2u_LKocNfBJeWWDyhNzDfOs8tgc11JfZ X-Sonic-MF: Received: from sonic.gate.mail.ne1.yahoo.com by sonic317.consmr.mail.ne1.yahoo.com with HTTP; Tue, 9 Mar 2021 15:05:06 +0000 Received: by smtp425.mail.ne1.yahoo.com (VZM Hermes SMTP Server) with ESMTPA ID 8035a072f5ee31803d67cfe7edfa7010; Tue, 09 Mar 2021 15:05:04 +0000 (UTC) From: Casey Schaufler To: casey.schaufler@intel.com, jmorris@namei.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Subject: [PATCH v25 20/25] LSM: Verify LSM display sanity in binder Date: Tue, 9 Mar 2021 06:42:38 -0800 Message-Id: <20210309144243.12519-21-casey@schaufler-ca.com> In-Reply-To: <20210309144243.12519-1-casey@schaufler-ca.com> References: <20210309144243.12519-1-casey@schaufler-ca.com> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-loop: linux-audit@redhat.com Cc: john.johansen@canonical.com, linux-kernel@vger.kernel.org, linux-audit@redhat.com, sds@tycho.nsa.gov X-BeenThere: linux-audit@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Linux Audit Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=linux-audit-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Verify that the tasks on the ends of a binder transaction use the same "display" security module. This prevents confusion of security "contexts". Reviewed-by: Kees Cook Reviewed-by: John Johansen Acked-by: Stephen Smalley Acked-by: Paul Moore Signed-off-by: Casey Schaufler --- security/security.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/security/security.c b/security/security.c index b88f916e0698..5d3dad5f800f 100644 --- a/security/security.c +++ b/security/security.c @@ -834,9 +834,38 @@ int security_binder_set_context_mgr(struct task_struct *mgr) return call_int_hook(binder_set_context_mgr, 0, mgr); } +/** + * security_binder_transaction - Binder driver transaction check + * @from: source of the transaction + * @to: destination of the transaction + * + * Verify that the tasks have the same LSM "display", then + * call the security module hooks. + * + * Returns -EINVAL if the displays don't match, or the + * result of the security module checks. + */ int security_binder_transaction(struct task_struct *from, struct task_struct *to) { + int from_ilsm = lsm_task_ilsm(from); + int to_ilsm = lsm_task_ilsm(to); + + /* + * If the ilsm is LSMBLOB_INVALID the first module that has + * an entry is used. This will be in the 0 slot. + * + * This is currently only required if the server has requested + * peer contexts, but it would be unwieldly to have too much of + * the binder driver detail here. + */ + if (from_ilsm == LSMBLOB_INVALID) + from_ilsm = 0; + if (to_ilsm == LSMBLOB_INVALID) + to_ilsm = 0; + if (from_ilsm != to_ilsm) + return -EINVAL; + return call_int_hook(binder_transaction, 0, from, to); } -- 2.29.2 -- Linux-audit mailing list Linux-audit@redhat.com https://listman.redhat.com/mailman/listinfo/linux-audit