From patchwork Thu Apr 7 21:22:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Casey Schaufler X-Patchwork-Id: 12805719 X-Patchwork-Delegate: kuba@kernel.org 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 4F9E0C433F5 for ; Thu, 7 Apr 2022 21:26:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231539AbiDGV2R (ORCPT ); Thu, 7 Apr 2022 17:28:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231467AbiDGV2N (ORCPT ); Thu, 7 Apr 2022 17:28:13 -0400 Received: from sonic305-28.consmr.mail.ne1.yahoo.com (sonic305-28.consmr.mail.ne1.yahoo.com [66.163.185.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD1C319B05A for ; Thu, 7 Apr 2022 14:26:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1649366770; bh=KzbFwwhuwjYfTBU4tfTxK1dAwBTSVWuzxkwCQg5qsUw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject:Reply-To; b=oSMFN1NXgj5nT4hKPSc4GG+4fnWK1CZ5bjUbH8NTGAm2xjEvWr+dyqPBM8nnflIDINXN6kldvhV2L6KESnmzDIKZ+brRuUkxAz5eRGoew5pSKjHRQuGYiOK9V9nSDgnezN1ln+oMlR40e3vdM70FVRvHbM+aZgxhXOdnmNuyY3ScIgiclZJf1PlpzVHOMAbwNcaLDeNVzJw2rI56tblV2b9KExw8NSmlQeFLJRQzLR7U3I0d3gp5W2IXbRTVIf55ZhLATcW72j4vJ7Lq4LWHE4C0rkl6cxNzV50aGh4u8dY8Q3Ed97vHQ44tP9jdE1+7eOgZV0E6yy4HY5sUbs2nsw== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1649366770; bh=xDz3OU9PDS8Hz3vIt1H+suPQtNOH14jBaooUb2W5sc8=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=kLrtIzaVzKmcpaXa6VckGZznZoYy7j7+KWT1RGKrgmsE1nodjlQcYCrizD2SwhIZDe4AtA03VLPDUxewf14n1+wayQgGn95bRNNAtnPivYtvGQVQdZQDhSIAKr+rQWWqXowLXCFltKw59+wd6qVims93HSqne5yNGo/0uCaDxpl59TMeHq68y2zhu/YiqL9nNhkvnz90hQwq5IRLNJUU5O9derX04otTJhfzqIyxp6ZnfskKJMdT5RwaqNht+cFj8wh7cat5JNrbywsZ/ZoObW0B+ZWyCyFb4h8BKvglGBwZn2thmIUuLi86GBWgbtOPvkNWyQSMPaw9d/NAN3ywiw== X-YMail-OSG: MzyUCcgVM1ltKIjPm6j7qa.8FIaE6f6l9wXggunUKktQq5N72GVK1ey1w1qZZbc xg9pb.0AgGm2ZmHNKflOpl6ZyT7YG_Lv3YoC14bNlfWUas03qKKM2yk4aSHnUjjZbv4yO8gbho3K rikpppNY51LNf_XTBbLcUIO.tdXBxPmC.4TicHa6YNbf3HpnZQAVAJ2PyUWRTcTg077MLbulL5_Q mYjDuEItFlOWudyI_EWutNBXzXT5Y4RL8kWgirywC7.38_zUNnu_VHH9FMG2SbdX6oM1AW7r4K8A Sst7dlSSI2NhttzYzlb0qMvUyYJt_oSS_deIFDs1kGTUTnnZ4CDEx4lg6mugQqU801z5gz3qp.tl TU7cXj4B5gcZT2kIpvXGnUvrFDCekX6ua8u_BSVLRbLSAFXfPgZ9PGqkda4En3pxLtwBzMXkQjCC DYsmsH1.by7_dVtXlJfxzYagZPLmIUf7T5KKFSpV.FEdSNGItRbLT2PMfoEJmgDCR.5cY1PSEJVe 4mTf5PRtYHGJ95abB_86el.9L5zsjZ1LQ_KW.fOUud84UobC6bwPaPfrC9mJuZ51_gk3ZlrGK7_h EnkvsQQxNd4.ebaiI7jZjQB..l8yBhOGh1Sm3AI0gOrCJFfW_11tC5vACVmn5j8qNxVCPHkXPqjK xHX6HiGvT4WUYhPHHnZyhkWujjMXnhXaK8yqqC_qhG_iFZGk7t3PY7LMN9oITyx9iEsQkKq4EZx2 QmCfoKhk.cb2yiqLbuCCwssu7dTSZMlBzBesIZPlEvLPRiGtvdO8N1oTKB1BJwME9ufVL3fYWmvS mBFoyUBbsIstgI9KhIUAFnTwx5VlJapGi79vO7RL0nrKULsAEk224O8wkTRl0WYQhJzlUcKV1ggh 6rdJ1Rrjomsz.jMgmDN4JipHcdCrUVkXVyqfT1_P8syoxhk6UwVolEwdM741Z7SVtosR1b5Xadk5 flkfMTlOs7D1OoEENmJDD_u2.kIbSumkVyNAhR3Uxjvfulp12eQV1CK1Zuaerrjjs9qsj14X7rar nPT7EcR.AZn9eCIzY2xbeErQFryYTyjYR53qfhovE9THT9m.VNCpAPrna6UZgD8924nheQbpbEPk iaXqmYmp7scZ49Nh2n3Ucon3b71O8tojVZ9Qwm_s0ZceyK.aw8A6qiTan__N1C8iJ6YetyXp9irU r20ihzZAHE6UI6arba0q.PINjAezaoD2vA2W.1sQZOkMtX6qJAlUKVBV5xbtphfvQV9uQtVgUjgb JwGgZCy4x736XzDB1Uit.RmXgbBChy0tfPkbAQNzSJGYyE.CCQTYz2lxHthzhelwHppBZvGByDrM W2ETLeMBmAhgDPJ5v4H9RgS6PsN1UE9qx6XDdatO6zN0mc0kTfQIdMts6hFORf0mJoXZJh6QHPXc LzLurR4AbLAaqzY9rkUl9iVHvlwwsxFZJEXBGLQa7.dfQ.6L72qwuEvOVRNKYhMh2xRZlSqIUWbB OcuwWSChxeb92yIjhcwNblydWxgZ3_bQcm4aXMXKDapayZ.RBYfE9Ssxpt42KpzONeSF9hd73jmJ DQkOCHVOFLWJDOvuy0DfKIXpa9zvPd8fBiG9mFOWrCYQvpjsXWZZwwNw5NOkS0DJf17pYt5Bal6q .yfLXPwWqMdiOOj7XDh6QpEArmGvkg2Y_eLf2MKqebD_FZewxIpjkwVJXvWu0i1PgyX74vePzQXG S06FhHovs00kiUG3RvVQ1ZNnbOhpGfIXNjSZlzYsRSkMpr7Vz441Vi2N9kZDQ9hmLCSy8Dil.NmT g1qjvrsq08RSARU51K1dfANh5BN9fyvFUWhLpxdoU_iTCZTWqCsKssV.2PP2uUi99iZz0OHzRDKc 3u26ZrFEiJIxBVftFpWQVtF5P.3V1nxYDFXaTxyl8oMj7bON2YEnwhNMqG7bqiaKtZK4xMQnY0cH 5eX7dYbpEA6lC8XCXOXofZzNqOj8G6aXDhLXv6XWXHxw1Kycl1qGISQBa8ipcMJezK6SVaL6JNuo 2fvZAI.KmW4z11OabV3UlHFMkON3TJ0uaQmerAuqp6jRf6vbRs7AGOFHViK1Fmwe19Jd1hkUJWqh trsndhZigYiDLrg4YZNqlfrxMJzODSkOJATUp0f3pQBTJjEKEtuTtNe0nL802lsxi.djUXWG17mW DhNIfqzzuRmxy2ewK0m_DxdxiKgYMFRyGqy5GWCwUtJhFPz2UAG8BREffj9aI2c7UVV2CNATtHD1 4E1d4lr8.saw36tQUImulFcEVULXS_Z0KG.gSlkti9rE3iqVKLEleDorvkhmqoAcxCI5kbf8OhrQ 9wyU- X-Sonic-MF: Received: from sonic.gate.mail.ne1.yahoo.com by sonic305.consmr.mail.ne1.yahoo.com with HTTP; Thu, 7 Apr 2022 21:26:10 +0000 Received: by hermes--canary-production-bf1-665cdb9985-zm65g (VZM Hermes SMTP Server) with ESMTPA ID 1b8a787888cf9c0809abffd2a20a44f0; Thu, 07 Apr 2022 21:26:04 +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, stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org Subject: [PATCH v34 08/29] LSM: Use lsmblob in security_secctx_to_secid Date: Thu, 7 Apr 2022 14:22:09 -0700 Message-Id: <20220407212230.12893-9-casey@schaufler-ca.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220407212230.12893-1-casey@schaufler-ca.com> References: <20220407212230.12893-1-casey@schaufler-ca.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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 e9f185e9162a..310edbdaa14f 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -199,6 +199,27 @@ static inline bool lsmblob_equal(const struct lsmblob *bloba, 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); @@ -529,7 +550,8 @@ 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); @@ -1384,7 +1406,7 @@ 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 3925d38f49f4..adea727744f4 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -791,14 +791,12 @@ 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 ac4859241e17..fc0028c9e33d 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -860,21 +860,21 @@ 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 8490e46359ae..f3e2cde76919 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -880,7 +880,7 @@ 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 @@ -904,13 +904,18 @@ 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); } /** @@ -931,7 +936,7 @@ 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 @@ -953,13 +958,15 @@ 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 e9f1487af0e5..f814a41c5d9f 100644 --- a/security/security.c +++ b/security/security.c @@ -2211,10 +2211,22 @@ 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); @@ -2365,10 +2377,26 @@ 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);