From patchwork Thu Jul 22 00:47:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Casey Schaufler X-Patchwork-Id: 12392611 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,URIBL_BLOCKED,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 EEC68C6377A for ; Thu, 22 Jul 2021 00:55:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD71E61248 for ; Thu, 22 Jul 2021 00:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230031AbhGVAPT (ORCPT ); Wed, 21 Jul 2021 20:15:19 -0400 Received: from sonic314-27.consmr.mail.ne1.yahoo.com ([66.163.189.153]:33417 "EHLO sonic314-27.consmr.mail.ne1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229879AbhGVAPS (ORCPT ); Wed, 21 Jul 2021 20:15:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1626915354; bh=B0E2mJi50VrupNDUfbc6O7BsZvL9dT3zvHnoCNS9qz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject:Reply-To; b=Hha/LrVo5WrtANYQiSZs7NsNjkZ3rfXgz0OQFzsi5PWYXLd8Ex53dnmzW6gmKLIzqu353ibLz68a4SJCyD4xnMZq6leG0vxR+yffxLk7zy+WHkc2dzhQZhoJpc0xl51NBQaTFhyx/dFMr3L2Yt/VnriHDEbzrZh8Hf3lGCwMFY2m/rV6Sm6vm6I2uG2WWCoIkOiW3nSQ6ny6G9DZnR9GzyBdHvqWwhUN4lHKQYDmfD1CBsJFyfbdskjPAOy552N6CyaxHGUrGui0yK4a3kdTvgavk3kFXo4jMc/lVVK5NV6ReVm90kxtqIl3EtLqWXxZaveIFcU3w4pesbhBu1RHFw== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1626915354; bh=Lr8GxeVHv9fT+/A/P/OuUDvVRuowfjIYU6akGrFlPng=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=FjGECPLqlgy4lG0T+cCtxPExRU3EeyFLo9Q5AKLVFTLbBZ16G2LklwNDm6ItDJ0HJP2krr328yNDSmRArL+1L1yPxDZ9CVs2Q2p3mLNDcgmhBw3CDlHJ2kZbcYtckTeOtd75aoYCHfCX5PdN13Zk1qe/nsmM4I/I5oFkOLS+kVnV0O7bh6tPSIAVQsE9XMqYkbrDnuwgL13fgioVn22gfSXlJ2RMdxL/sXxdbhmshYKx3vI5+NBscbUxP9HOp6Pek0jdnjqPLjIdbmMFV3k0DHpsMYcSk+hz7hOGi0wGtAB1jmzE0ZRn83LovKTXL6vkl1uKoUnRV7ifA0mL+7vhQg== X-YMail-OSG: bXQnCT0VM1m41SDQ_psBSVOGibKMrEwP4whtOCxoZ_reQtMTN2KBTeOgH.ZVaRk hBDtu.ON1eyF8O2juOoTYQ8LhGU5I2fn8cbaY.2xHVZLASL22mja6N5mYffsN.PuaUpe8TfMQS0_ Ind6OAp69rvR_t.LGk2ZGN235XC5DJ7bDyNvy8Mg7fIaKbsAdcG57p.GMg9unOqQpF70NHNro_Nx jwMd61Z.ecVVshZSjXmvCbcC_xh5NznnhF.N8Z6TXTbkCcLmZeeBdEXyrbALYD_q9x0hj5JnbuKv Krrvzzk3VmwhQfi0bkNNlqYMYhs8yuKhDvwvDBlqUOAVigJsRoiWvoN.EEzKIP3qWd6yVYrs1bML plJ8RrCdEOfcOYBSKC_g.kuY4iIJsskAs6ewpXnDxBuoMEfCc70Pb6EFnFO0VDTK13hX8tHmnlrQ u05s.JCK096PRr8R.b5y7nB5e.NJwdzLlFuO9Xw__DlZlcMFaUvNeFdGVnFOksYeyKd2N2dnHqSK 6GOgHVe1ESwLKTXBRboVFQ16Co9kkZGFJZbD1uhxc7dBe9ifN9lfCJSLYkIfBO9TRmoJoeJnYTpS 1FP_OemwbeHiLXMcdFIybs2DUZ6h8DJpPSiDEFRPrFEYcTTTiD0.nKONawb8b4tS96SGdKFCt5K5 EF5F_uX6YDljDv0GS6LBY60BGseakKHVdrp5pGepDLzg9aM9p0eHE3RFuMMJOkG8g173yz8pc0no ilksz9QRxl6MPjE78c5I4fbTCWURrA28857ZlX3ydt7o6lM6zxF8rWgrzJw5B06TwPNoH9sXyB.Z 04ZqKPR1j_JR.GOPo1eDvFesX6Wm1tXTZ05GRyRO89qZ8IVcsbeOzB3iiCw8PfAo.be66W8vxiIv 5.DOIeD9e2YJ_Ud1KXPvMdBQIOYl3hwleEdAg3kuWwVhLIQeJLcFSxRQai1l0CZAEeWjdCsdy8oM FoyFZT6hi3Bo0rPyoeKK8kYWE.N42jccn7isIuCF524JPim6xHM8mC.AlyiDld3d87NN4J.rtvbl COZlQEyRXc79YQOx2OwbxNj3P.Z550A7AezOvvOz5LeKRlpR_tLQ0ocyti0a1nkksEEMq6eNVbPT sptuSexzmCoOvS.FLg7CGuRS2kh54FqIqy2DZKPlBMOuVzFNChuoyJStkuh98GFX_5vaC3CiTU4G u26I2cf_Qdr1OcEHviGRa4PcSKuAtss8xASYb984Kftn5D839jHCK9Rwkq1B1tiNmsO61drLOMj1 pftK23GJ0.hkJ3_Oa19DQ7O.J1cAo9hkGIar3HXLzsfXhkxAgeGwf2H23z7O06wNpVYXU7kG3JB5 Uv_kpqbnVytdcW2dKPFZsmA8H9El1ySjB.jq9HCO1I5LyTNxsBzMpEJ71eWBdiBuo0VH0xUCI_1l k.oDQC_Obp1KKMxplVmanrZtvMASY.bHQU0icPs0a7OLaIqlRfVtTKH655xS5wk3hQSK4VunGyYN SmdPoX7v09ba1rDV6x3m0.L5EGdeVeiOMlEnjvaX8ngrMdF9bClvZNX6AKIL6kST0YGUGQzryBg_ a_F1xIcM2.HOjkSsG09Sudid3Z7dfqBY6GFy9HBx.u2wQW1fXEN6eD84QfHtuelBWry9nUBm.oUX SCAQbuJSM5QB3C.UeQ.yUAZJK9JjuDiQa5MsCVltRRsWr2BJveSC3hT4KvHyynw.LA1T8Mh0Khwe JGHdaiWH.lHIFOhKu5UZZsABA.MPH27BYCvYw5ZXXX8ho._h7_dcy26nbwAjsP1ro.4oEtufh8DB 23R.ucIrpB4HLcw4OXPTtCNxitNXylQyxpaNqOiowpwgvKvWgqDd5CwUQHmhNAwpmFr1gWcPRg9i aon8FxYPO.GGU2DuZQ_NC8Fcj2BpqxJeYZYFgS_kXb3ShOYevtpFa1YIdxV4v655QaIhSMpIKwhd 5ufgI0ceFsqlIoUZtO2IWIu6oiF1F7YpBSe9TIIdxTsSsUNLfwF.VAVdqPdm8hepteUPg7kqirba IKEbxdGfKNshAzYalKiM710VDBfy.MHOH3C5LvkybWGWJB.n6fmh5VwcMZpwxyWvsXZ_7Yx1i1z9 iJwgfLBxn8XfeimpZBDgHOdFWVuMAgJ0YKBMCFOY5RiO6104dMbV._OnDZKTx3q431s2qIdFLOg. 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CN9lmTuTn66s9f8OUTuSkkW916kv4tcUhxrh.rm7RtLyBqXBhu0jkawJxRVmRCeIX7QyY9Rs_p9y hfTjDQ_9Vlqy5lZ.DQ5BvVbP6C3xMA3r9E86VKARdJOW4U_EEkYPReR5.qJTEMDzsBj3apBl2zZo 8YafSh_4dnJr1nvdYkTDIxMG8q6O0QleR8FNUs28FMCqiSpHibWyupRrVRi3HMcjTsTLk7ICJk8P 4A3R2Z5KD9tF5yMModqm.EcQ2xHemfe4CBHuXAlIxvJXrfd2FSf7Ym9NWC28dx8rnpFEfTA-- X-Sonic-MF: Received: from sonic.gate.mail.ne1.yahoo.com by sonic314.consmr.mail.ne1.yahoo.com with HTTP; Thu, 22 Jul 2021 00:55:54 +0000 Received: by kubenode505.mail-prod1.omega.bf1.yahoo.com (VZM Hermes SMTP Server) with ESMTPA ID 7f76660ca894cc8d842d2e9b1dc58c45; Thu, 22 Jul 2021 00:55:49 +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, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org Subject: [PATCH v28 07/25] LSM: Use lsmblob in security_secctx_to_secid Date: Wed, 21 Jul 2021 17:47:40 -0700 Message-Id: <20210722004758.12371-8-casey@schaufler-ca.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210722004758.12371-1-casey@schaufler-ca.com> References: <20210722004758.12371-1-casey@schaufler-ca.com> MIME-Version: 1.0 Precedence: bulk List-ID: Change the security_secctx_to_secid interface to use a lsmblob structure in place of the single u32 secid in support of module stacking. Change its callers to do the same. The security module hook is unchanged, still passing back a secid. The infrastructure passes the correct entry from the lsmblob. Acked-by: Paul Moore Reviewed-by: Kees Cook Signed-off-by: Casey Schaufler Cc: netdev@vger.kernel.org Cc: netfilter-devel@vger.kernel.org To: Pablo Neira Ayuso --- include/linux/security.h | 26 ++++++++++++++++++-- kernel/cred.c | 4 +--- net/netfilter/nft_meta.c | 10 ++++---- net/netfilter/xt_SECMARK.c | 7 +++++- net/netlabel/netlabel_unlabeled.c | 23 +++++++++++------- security/security.c | 40 ++++++++++++++++++++++++++----- 6 files changed, 85 insertions(+), 25 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 332df8a1cd4d..986a8f4bcd54 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -196,6 +196,27 @@ static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb) extern int lsm_name_to_slot(char *name); extern const char *lsm_slot_to_name(int slot); +/** + * lsmblob_value - find the first non-zero value in an lsmblob structure. + * @blob: Pointer to the data + * + * This needs to be used with extreme caution, as the cases where + * it is appropriate are rare. + * + * Return the first secid value set in the lsmblob. + * There should only be one. + */ +static inline u32 lsmblob_value(const struct lsmblob *blob) +{ + int i; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) + if (blob->secid[i]) + return blob->secid[i]; + + return 0; +} + /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts); @@ -527,7 +548,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value, int security_netlink_send(struct sock *sk, struct sk_buff *skb); int security_ismaclabel(const char *name); int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); +int security_secctx_to_secid(const char *secdata, u32 seclen, + struct lsmblob *blob); void security_release_secctx(char *secdata, u32 seclen); void security_inode_invalidate_secctx(struct inode *inode); int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); @@ -1382,7 +1404,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle static inline int security_secctx_to_secid(const char *secdata, u32 seclen, - u32 *secid) + struct lsmblob *blob) { return -EOPNOTSUPP; } diff --git a/kernel/cred.c b/kernel/cred.c index ea36ec6e1ad8..38b00a1390f4 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -798,14 +798,12 @@ EXPORT_SYMBOL(set_security_override); int set_security_override_from_ctx(struct cred *new, const char *secctx) { struct lsmblob blob; - u32 secid; int ret; - ret = security_secctx_to_secid(secctx, strlen(secctx), &secid); + ret = security_secctx_to_secid(secctx, strlen(secctx), &blob); if (ret < 0) return ret; - lsmblob_init(&blob, secid); return set_security_override(new, &blob); } EXPORT_SYMBOL(set_security_override_from_ctx); diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c index a7e01e9952f1..f9448e81798e 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -809,21 +809,21 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = { static int nft_secmark_compute_secid(struct nft_secmark *priv) { - u32 tmp_secid = 0; + struct lsmblob blob; int err; - err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid); + err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob); if (err) return err; - if (!tmp_secid) + if (!lsmblob_is_set(&blob)) return -ENOENT; - err = security_secmark_relabel_packet(tmp_secid); + err = security_secmark_relabel_packet(lsmblob_value(&blob)); if (err) return err; - priv->secid = tmp_secid; + priv->secid = lsmblob_value(&blob); return 0; } diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c index 498a0bf6f044..87ca3a537d1c 100644 --- a/net/netfilter/xt_SECMARK.c +++ b/net/netfilter/xt_SECMARK.c @@ -42,13 +42,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_secmark_target_info_v1 *info) static int checkentry_lsm(struct xt_secmark_target_info_v1 *info) { + struct lsmblob blob; int err; info->secctx[SECMARK_SECCTX_MAX - 1] = '\0'; info->secid = 0; err = security_secctx_to_secid(info->secctx, strlen(info->secctx), - &info->secid); + &blob); if (err) { if (err == -EINVAL) pr_info_ratelimited("invalid security context \'%s\'\n", @@ -56,6 +57,10 @@ static int checkentry_lsm(struct xt_secmark_target_info_v1 *info) return err; } + /* xt_secmark_target_info can't be changed to use lsmblobs because + * it is exposed as an API. Use lsmblob_value() to get the one + * value that got set by security_secctx_to_secid(). */ + info->secid = lsmblob_value(&blob); if (!info->secid) { pr_info_ratelimited("unable to map security context \'%s\'\n", info->secctx); diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index 2483df0bbd7c..c29a8d7a7070 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -882,7 +882,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb, void *addr; void *mask; u32 addr_len; - u32 secid; + struct lsmblob blob; struct netlbl_audit audit_info; /* Don't allow users to add both IPv4 and IPv6 addresses for a @@ -906,13 +906,18 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb, ret_val = security_secctx_to_secid( nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]), nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]), - &secid); + &blob); if (ret_val != 0) return ret_val; + /* netlbl_unlhsh_add will be changed to pass a struct lsmblob * + * instead of a u32 later in this patch set. security_secctx_to_secid() + * will only be setting one entry in the lsmblob struct, so it is + * safe to use lsmblob_value() to get that one value. */ + return netlbl_unlhsh_add(&init_net, - dev_name, addr, mask, addr_len, secid, - &audit_info); + dev_name, addr, mask, addr_len, + lsmblob_value(&blob), &audit_info); } /** @@ -933,7 +938,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb, void *addr; void *mask; u32 addr_len; - u32 secid; + struct lsmblob blob; struct netlbl_audit audit_info; /* Don't allow users to add both IPv4 and IPv6 addresses for a @@ -955,13 +960,15 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb, ret_val = security_secctx_to_secid( nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]), nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]), - &secid); + &blob); if (ret_val != 0) return ret_val; + /* security_secctx_to_secid() will only put one secid into the lsmblob + * so it's safe to use lsmblob_value() to get the secid. */ return netlbl_unlhsh_add(&init_net, - NULL, addr, mask, addr_len, secid, - &audit_info); + NULL, addr, mask, addr_len, + lsmblob_value(&blob), &audit_info); } /** diff --git a/security/security.c b/security/security.c index 69474918be8b..1621a28bf9c4 100644 --- a/security/security.c +++ b/security/security.c @@ -2193,10 +2193,22 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) } EXPORT_SYMBOL(security_secid_to_secctx); -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) +int security_secctx_to_secid(const char *secdata, u32 seclen, + struct lsmblob *blob) { - *secid = 0; - return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid); + struct security_hook_list *hp; + int rc; + + lsmblob_init(blob, 0); + hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.secctx_to_secid(secdata, seclen, + &blob->secid[hp->lsmid->slot]); + if (rc != 0) + return rc; + } + return 0; } EXPORT_SYMBOL(security_secctx_to_secid); @@ -2347,10 +2359,26 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval, optval, optlen, len); } -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, + u32 *secid) { - return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock, - skb, secid); + struct security_hook_list *hp; + int rc = -ENOPROTOOPT; + + /* + * Only one security module should provide a real hook for + * this. A stub or bypass like is used in BPF should either + * (somehow) leave rc unaltered or return -ENOPROTOOPT. + */ + hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram, + list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.socket_getpeersec_dgram(sock, skb, secid); + if (rc != -ENOPROTOOPT) + break; + } + return rc; } EXPORT_SYMBOL(security_socket_getpeersec_dgram);