From patchwork Mon Dec 13 23:40:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Casey Schaufler X-Patchwork-Id: 12674959 X-Patchwork-Delegate: paul@paul-moore.com 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 AB64CC433F5 for ; Mon, 13 Dec 2021 23:49:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244263AbhLMXtj (ORCPT ); Mon, 13 Dec 2021 18:49:39 -0500 Received: from sonic306-28.consmr.mail.ne1.yahoo.com ([66.163.189.90]:45505 "EHLO sonic306-28.consmr.mail.ne1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243322AbhLMXtj (ORCPT ); Mon, 13 Dec 2021 18:49:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1639439378; bh=jED1FKxellw4KtQDkWf6Z/5uafpV100mgrllKbb8X90=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject:Reply-To; b=DEIbbkGO6YIqi7gr3KJm9RTXTpuAYmaPK4b2ckhYa9hDnniHq60fPqZHdPWpbIgibhGLXTyI2hnOpvmilltqIqsucKpjOshaGu2e2y9ynhTqOdhr71BeWgVR98KCrpFagjysirbdVY7PjKKvvcIZsjBCgqYjwyb3Bz7WxVxSZATD1KPr/vlPF2xVs5mnb6xuSgE5QnYVtNAqXQQjhlZmWd+PwnF+A+g4T9eCJE0XQ9XjaNn1AQLL8wDIuzKf5eL6iEYHffLuQYJXOzv7Kg0bCS02K8BUc0D4/cMW51vqccoauVVeHT7Hf7X09XlkF6m+GV5RQ+I22U9nj6POuTFKRw== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1639439378; bh=V/ADtwObiPT035hBwB4n02igK7ErvLlMXO92/D5Wt8Z=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=kDB31NVsOWacd5kJumDs9pfT4GG+uPgCxeteU8YZLxLbpohVgT2O5vHy0NO3W7aA0zSPgUbJLDkyCpNlGZPO/q4BAvaCL8WcaK1dvL95aIl5gL+IXcxxz4htcNh8yX2Ap3CZDpY3Z4nnDKTw5F51EJUNAptxuspiJ9UHUgnw9tqWGmYb+cuOAKcTB5Hpsrppe63/9l9Hh4859itgwsBsCJEgrurwICW2W45O6X+2fRjQ3fIJJdrfwf0j5GZIWt1+JXSGe9D2+zUlBykZnv1WMJmmW1dF7M9urmKfpIQvHwNi1bw9CINQiIeHCxgMLTOwMbTH1GA2HGbwicRONGMuJA== X-YMail-OSG: yxJ0gS4VM1mvuKEFInuzdpAPEHoEFSCzPrBQDCOuxRhSVefQ9ewJ5LrKxndhrSM oBKRpVUT2u8VpLCnsA4.hCyQMgXkqPQV5fiU.b_dmo4peXOevUU4j6zbJTdpwCT4giViHf49xtaJ D6x7Rr7ePN5s3cW.13az9qExpQ7m8iwmtwD2.wNteznkx586M..1GYcljFnyNf0e9OXsiJ.s3Rum xrZACBEft800Q0yCPk.WFN0SoEqo06dYfHChE1CIGGFvdPS8aDmLhfHrp7of2o65cJP.dDCfiOFH IdggmbJv0kpCNx6NIb7WYOIGgQ0vMkZ_4wWBi_euiM5alMg1hpC.fQ4YfjgWcQcRhMHpse5OQ1iH vsPPaFQsrixonA9U5fOKOfAuGLZBToLAb0T8UHzjyfzUpJEGnwdIl0axH9WZhObocA3InBAiw_GP .ZygM3Zu2AqwwivqnCLTYEONOgiq1jqY0iTjvnjojehtnOMr9Uufv9Rl0SO371xGPw_epsaB2wb2 NnL.R6.yfV0CYo76IXny046riaPLW9pbgi1IkyO0l0q01uBZurRBd.46VZ8ISYB5tSOuIuc1Z8Cx 6VSHtaRjepIE4BYHTS97O_DG5yTROKJhg_lnYxL37DcGvtw_.HBivAxzgVAh3f5CIhc_ts_XhVoG ndJMrOarleASemNaUjTs991aOYAyb72HuOvWILgIWnKzXz7Rbkcj38a7xmxaaxt0x45bp63Hbmsb 60gz_cPyDH0THVEL3mZs0_anIlmsMRNKUk75Aw6JBpxnO3_2wexH60c_EejnITb2yWRwaT43WGkV cWLep3OGk5R4JyqK64LI4at_qDj3kWr1w9rmnLLNxfqXDxSTa4YpDBYej8Umr82CBnatovbR1GjR oFybsMT9SN5eqc12xGbbXIkbuy3qIOpSHNTG.m.H_s8ZIWBuOeFcRF4ONqexzafKzP8KKuI_5l2p fsDeqTTC_FsGMvudP9Yo9VM4t1Zv1ABp8YCBnra5UbeKQyJ3uiMExgiDTLJDT9ben53rh27jgVhL 4aIF0t_vhltqEDQl4TO6U7WKZHjo80vQdOKCK1pgjS7gbQLSH0w8eoCACMjIQYAe9E448Ynrcfnu ALvznzjnbda4b2SkV.Rsw5X4NTIEAOPZNpLdUo_oajMqQ3AHVCKBQKvB9OImXWKZ8cY1g.nFm9Tx oTH19CM9YhOm2cPHHCOgj8mvpEOsKNwTkcKdSh2DmOjKDo1bkQdd9QsynNAq6SjLdudD09Cl47gW 2c73FejA_PT7kBKmEc_pxjsE49alizY0cJ0QUci9gmlVtvsr9cziedUu4U71XnFWMdTwyvbb0CMP UVQAMWc_TnTTCsYk_BQjpbYR90I5w1Afb0eYXSqNJbT0RQ9Qiqs0gIZmFoibtWEJr0MOLRfY_Yy3 gA9VkW98HkeupgCpaJJTmxLAuoXtI6wf9cVWafpxzDbKRNCYW64MFp7BUW0PGxn3psqxFppLZ7wW 7NOPNjJ7IJE1QXLY1R9JmGlGY0s5dGsd.zxyud0BOdOZEMpA0uLhNaJQC1yyN_fodt0U_baqTjDP bknPzP6UgaP.Lu8wzvXgXi_Fz7s98vkl_otQq.dEiHGRG3ISqgUlE.4kTRtZXnaIAel7n.XFWKmC XGaYoQfWZ1i0KEdLqPtO3QYChwvO2n_K0ObRC0fz2oVXjLsnzmKzlvO6bHepDGjtj_Zjbydllk.s jGpx9fz_4l2o9leW.7FFo7z9NzyiXfxdpM54SPfehZvIgkHp5ajALDE9BYZg_18D0gidt1x0A8XZ uTo8uyjMtifsMtx9JOnbEcJCtJhCp3SSfUmPoiHvXtbM8eUscoyp2AuzNP3epL5xGTd7n97ZBa_k 266rlx09mw0cR75zOQ2xedLJkM0t9RPKdqIGWyCVWGRv0y0qY2gRyT6oDQuVsZXvFzR0mf6TkYIg odpjd4Mm.5Qz7hh301YwiXLvAqfPX8F27XqCIlhsS7QC_5A_L.Zkt4TTuFcHANtW3L_It0acJEKd Vyanji.mORQCXlDgLyRrIto_HcbSxBT6TEVqFcWmeV1n5eaxKDCL7qHdUwh580jX5Cpfzld.d7fV j7EaG2JiuPTksEiVq5Hj5OOlZHKRxu_O8inY3OwVu4FNEroYDALWZLaH5xrugPxofCGg.NPt23b7 dkwb_R02NjP3XdZZNAx2KC0Zdd2mjEu2NS_pdVsfYsHHi.GoYzBgIuVWdoepqoA0EEpQ5qrJLWTN SEeXqfDrUjqdLmenbGXFinvtSdIxKVZMng5iHHR4.oxrzJ7KT4Uqc1cDur1Onw_RCHfqFUSHt_Ae Vf8z14KGi4OL24U_4wUId6luhGjE0zcW37qdvV7sedew- X-Sonic-MF: Received: from sonic.gate.mail.ne1.yahoo.com by sonic306.consmr.mail.ne1.yahoo.com with HTTP; Mon, 13 Dec 2021 23:49:38 +0000 Received: by kubenode527.mail-prod1.omega.ne1.yahoo.com (VZM Hermes SMTP Server) with ESMTPA ID 3c37c5f8f0988af181e864687125ff70; Mon, 13 Dec 2021 23:49:33 +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, sds@tycho.nsa.gov, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org Subject: [PATCH v31 08/28] LSM: Use lsmblob in security_secctx_to_secid Date: Mon, 13 Dec 2021 15:40:14 -0800 Message-Id: <20211213234034.111891-9-casey@schaufler-ca.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211213234034.111891-1-casey@schaufler-ca.com> References: <20211213234034.111891-1-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 aaa63bf5026e..8a547fc4affa 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -198,6 +198,27 @@ 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); @@ -530,7 +551,8 @@ 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); @@ -1391,7 +1413,7 @@ 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 e5e41bd4efc3..a112ea708b6e 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -796,14 +796,12 @@ 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 fe91ff5f8fbe..c171c9aadb01 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -813,21 +813,21 @@ 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 566ba4397ee4..762561318d78 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 171e2fe66e5e..7ae68b6ffc7f 100644 --- a/security/security.c +++ b/security/security.c @@ -2195,10 +2195,22 @@ 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); @@ -2349,10 +2361,26 @@ 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);