From patchwork Mon May 25 18:24:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thadeu Lima de Souza Cascardo X-Patchwork-Id: 1297519 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 49W59C5crwz9sSd; Tue, 26 May 2020 04:24:47 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1jdHmG-0008Ss-G8; Mon, 25 May 2020 18:24:44 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jdHmA-0008Qm-JI for kernel-team@lists.ubuntu.com; Mon, 25 May 2020 18:24:38 +0000 Received: from 1.general.cascardo.us.vpn ([10.172.70.58] helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jdHm9-0006Ix-SO for kernel-team@lists.ubuntu.com; Mon, 25 May 2020 18:24:38 +0000 From: Thadeu Lima de Souza Cascardo To: kernel-team@lists.ubuntu.com Subject: [SRU B/D/E/F] netlabel: cope with NULL catmap Date: Mon, 25 May 2020 15:24:13 -0300 Message-Id: <20200525182414.638878-2-cascardo@canonical.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200525182414.638878-1-cascardo@canonical.com> References: <20200525182414.638878-1-cascardo@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Paolo Abeni The cipso and calipso code can set the MLS_CAT attribute on successful parsing, even if the corresponding catmap has not been allocated, as per current configuration and external input. Later, selinux code tries to access the catmap if the MLS_CAT flag is present via netlbl_catmap_getlong(). That may cause null ptr dereference while processing incoming network traffic. Address the issue setting the MLS_CAT flag only if the catmap is really allocated. Additionally let netlbl_catmap_getlong() cope with NULL catmap. Reported-by: Matthew Sheets Fixes: 4b8feff251da ("netlabel: fix the horribly broken catmap functions") Fixes: ceba1832b1b2 ("calipso: Set the calipso socket label to match the secattr.") Signed-off-by: Paolo Abeni Acked-by: Paul Moore Signed-off-by: David S. Miller (cherry picked from commit eead1c2ea2509fd754c6da893a94f0e69e83ebe4) CVE-2020-10711 Signed-off-by: Thadeu Lima de Souza Cascardo --- net/ipv4/cipso_ipv4.c | 6 ++++-- net/ipv6/calipso.c | 3 ++- net/netlabel/netlabel_kapi.c | 6 ++++++ 3 files changed, 12 insertions(+), 3 deletions(-) diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 0bd10a1f477f..a23094b050f8 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1258,7 +1258,8 @@ static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def, return ret_val; } - secattr->flags |= NETLBL_SECATTR_MLS_CAT; + if (secattr->attr.mls.cat) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; } return 0; @@ -1439,7 +1440,8 @@ static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, return ret_val; } - secattr->flags |= NETLBL_SECATTR_MLS_CAT; + if (secattr->attr.mls.cat) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; } return 0; diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c index 221c81f85cbf..8d3f66c310db 100644 --- a/net/ipv6/calipso.c +++ b/net/ipv6/calipso.c @@ -1047,7 +1047,8 @@ static int calipso_opt_getattr(const unsigned char *calipso, goto getattr_return; } - secattr->flags |= NETLBL_SECATTR_MLS_CAT; + if (secattr->attr.mls.cat) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; } secattr->type = NETLBL_NLTYPE_CALIPSO; diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c index 409a3ae47ce2..5e1239cef000 100644 --- a/net/netlabel/netlabel_kapi.c +++ b/net/netlabel/netlabel_kapi.c @@ -734,6 +734,12 @@ int netlbl_catmap_getlong(struct netlbl_lsm_catmap *catmap, if ((off & (BITS_PER_LONG - 1)) != 0) return -EINVAL; + /* a null catmap is equivalent to an empty one */ + if (!catmap) { + *offset = (u32)-1; + return 0; + } + if (off < catmap->startbit) { off = catmap->startbit; *offset = off;