From patchwork Fri Apr 15 21:17:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Casey Schaufler X-Patchwork-Id: 12815345 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 3CFC2C4332F for ; Fri, 15 Apr 2022 21:22:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354819AbiDOVZY (ORCPT ); Fri, 15 Apr 2022 17:25:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354406AbiDOVY1 (ORCPT ); Fri, 15 Apr 2022 17:24:27 -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 33860D557B for ; Fri, 15 Apr 2022 14:21:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1650057699; bh=KzbFwwhuwjYfTBU4tfTxK1dAwBTSVWuzxkwCQg5qsUw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject:Reply-To; b=hSiJfrWFbHdl9LZfihf5S2AllUB5Qm7fOY1kkQw686UfN/qntdyQrepvqmGKxfWCIN48ZY0Q7fhoaEGNua5S/VCYrf/yuS/tiHmuVhnQFmqNHuaSigeXZQkg6Fj/vM9pekjYisjJ7rcTqbKmbBZ8x+dBxhLsj/w+2e/fay6ovP8/3YCOLie3e+aXz+QHZsd+yYWtUpALrTYkzFOBb17O2SkCoBRTdK8j8cLgHUbE0d7Z8SEjt+TrslbFxnxrk+6cX9cpdVOXlKvB4sUUam5Lo46L3H+xf+FzalsyKVATuJ6sQ/0THk1cx9hHFl9OnrEhZrpUm2syTEthdIxt4xiOTA== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1650057699; bh=mVf3QpWqgRjD+PbmoMDGV6gWcwVi0wKV73OxI+rp4Ox=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=ioclYtID+oEIQ1WYd555hBg30Ic/x/tEz0mXXR6HgcVtZmIV8/2jqHIyczOYa3eg0m/gCMIN5pdiXiUxaymT9Zf+TwQU75rooAouB9PbSQtyDlmXLlj7QqAl237HdMyyKot1OsTviCk8csmqhczb8J2Y8+Rwr3+8Rf9leYJrL7KutFGTDEyLr7TGi+hBdQnbiI5pAmDpbX7ZJZeWu2vfoffqzSymVr3oeD1VBbPHC0sEgCA6BwMSjzWWjwGiqCijov1a+MEDdSP2D/nPtm208D7Osr+dbdrC5tZDBYmUqzQDjkpkqeUPc9teXzU+SUh/2+k8buqxNauKjJhSqZlmzw== X-YMail-OSG: aIXsmEEVM1k05ipWROgmw4DdM0fAIMtlMj_x9XSOp030ZAqEqSen.2SOgMrPgQB r0aSqB8QU._hWWYecQD09iOwjYmJ1CU9iPhPNUxIBurTXYyeBSvCD0M_ouTt7vDFWO1.n17amyD7 Gq08iqe1xYujmhj277uCwHseSiDPSc3NOYdPxEa1s4puyc_6WZk5PmspZbY3ZT7nxcRPgzP0e7pa 4hK7SCgvfDzRUCp6iJuQ1zzyu8e5Vv9ev7rhJzzgON9E5FSESQEOaHrlgvWeKL3XqmREX77bzyi0 zoisxBMrz18yzAIzfuRBPvYz_TMNWKl4X15rJTDeH8Mj3gDeVvcNi1lDme0ciuCAGdyx1BZUb2tQ Jax5aFmXnQwWzkrOSw706LPJfZID7MU0zLtx_OY.0Sy0wBstvBKJ3NXHeQ6I4_07rbaEqDS_yKMF _gYml.8vFvhTu5BpBIgJ1s80FF508BVkWVH_CxkgfjYfu3SOXXeIvXzbQI6RgjVSLD35visIBuAV zO528D5xZYr_6P5RZUwoOJfNJTKeU8BSibYdhTIdNpSBQ7d2OVFyZyPUatqpKksJ3DUrpRKkozsl RpFCU0AyZgQz0NtQKBPgMFZhYAOWgulFzWxSaOsvF2NcqaYYrqUpAjFxzjgOqssa9NSezDwS.zF8 BpscLvKDdzFgDV47CiN07l0RoIm7yOPq__7JWSqVQmFPzupt.z7NRH02zDGz.AcejofU3bQmmZVq iUG11J8KOWqgDmSPptSohaON.6MpRtBkyrfVyDqPuNAuOA4mmDRghaRNI5zxjK7JyI33dTpukSjx _jogT.Ii4LAn4pKr3ZpiHvvGcgmX0n5AHwMQdgtKALuLnr.gOtu72mRmVmNBtTI1oN140XbQgYhy dQ3aa_9H_z7BsmjhPRse1bEIgtSvDBY4OCMe2POoz4D93J79ChOAW8VIrM4vdCLjoGuSjn.FmgqK iQvu5GZBFdmHVSZGUa32BT9p51Ekko34EFdsCdDapkog71Ee6zFOemuajxMGSF6.lphG_jdp180K Q85gQ4AxQ0xy7f9nZ6wAW0kOzb7NCixOCiQbXk.X9k1N33EOTDkhFpMoL.9wuqHJ6i8GtfKqwnVk 3PFUcx6qhXqfFeNG2btIIcLNt_HdFMVe532.7aa3wknNOlT0_StWSglZuPa1FwhRORyopHrxxwYE WdO1GKtsA80PmYkt86xqO3njYb2EFx80T6.alDbrWs52UaPEpZw2EqbqdiuLI_GPlIs97sRkFQzb z9HyTM9dI0hwK4mxRlrkeac0iOknFEpMzkFo.oZCSBTKJpFbHdacGtxr3KpniL3mg8fOwOLK6hpf jRHtVi37zDRYEdtbsHYaIbLA_tZ3iEX.J3FIPspl8hbjPHUErH6f.VbZdJmLJ2uRrji02D7jdn8i BfwoFf.PFRTRa9v6W3hEP7VkmX1H8cskpTS8M7m8MhDViezKmOJaGpzhMWVPxgB806VeZ3mNnvZc ZxcmeroSfIlyo9s8_Z5JZ0kPwAVhp0Hbzq8GgAi70iVoG272orvqBQh1fOByQ18WX31YzvqZCoYX APKavoxzzMQwvZizcNJVAwaPyN9wW8ejcbbvv.bXQrnpXu5V51KQb8XlYzYG9YvBMnGF.mlxRKF4 Irz.kMZ.9IRNJcV0C1yB_q9vg2QlkQ61TKAarS2T49o7oab.iCohUkQ164WF6gcrwFLyreV4eAYe FxAOvEr5YuDg6xRDk9GsyPRr3A96vg_yzk1ArpUYWcZnlaQ2pA9MTXv.bsnZ9XUB5ySC647ftUjS dAJWAzw8640SsyYCwTjylLznPtjYWKlzuX4v_y8RBB28CBN3LxUd7PwhLZ5ojU6vwH0Vt3teXZkp .Xf5nXEiDpsFdbsYMjrNRZXimvS2ZLb7SQ5R8o2jb9ktOXQxUv3HWQZFN326xMQlzA2GSBqmnBfC JGNAQs7t.j7t7lbj5rxPJekRDIl_fKDe9XkkeehF13bQvc1caVvWH3BS9x0hhRHffbtyjehL.WZ6 5qf4ZQgKW_PQPOS9AGqz98nTlaw.6OMWfrBg6jqT0vtlAnb0tA81XU5Atd7Sg7vvREn3FQC4qqT3 t6LVqdMfmO8ldI.xP51qLFYDwk6voR8OIqNv3wKEvI1WRNwKhMJtzaB0Rw6HZVGrLRtAlDxRVBvD bOhgwJMAU5d6DKMD1Gk4YTFBlgJqnnyt5r3HTvnvX57zLBFP7r7RKkQWXgGizDJuAbIrFUlyNuiK CO2CDuz9h.70YHcafYkPS1UR.lpBt7l.6GwL.wYcLARh3AuB.xBnr2cLyd3pwVJAW1EJRoA9Pcaw XjdRcl1P7WN.4h.GxEhbcTcEx9HLeXXWhpMFIN4obsm23BejgWKbxwKiDh_bINSgYWI9y4MoVeQ- - X-Sonic-MF: Received: from sonic.gate.mail.ne1.yahoo.com by sonic305.consmr.mail.ne1.yahoo.com with HTTP; Fri, 15 Apr 2022 21:21:39 +0000 Received: by hermes--canary-production-bf1-5f49dbcd6-b5q4c (VZM Hermes SMTP Server) with ESMTPA ID c91982c747db758d7776974a874b1b0e; Fri, 15 Apr 2022 21:21:33 +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: Fri, 15 Apr 2022 14:17:40 -0700 Message-Id: <20220415211801.12667-9-casey@schaufler-ca.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220415211801.12667-1-casey@schaufler-ca.com> References: <20220415211801.12667-1-casey@schaufler-ca.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.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);