From patchwork Tue Apr 9 19:58:28 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Casey Schaufler X-Patchwork-Id: 10892231 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 098AE17E0 for ; Tue, 9 Apr 2019 19:59:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F176C26E98 for ; Tue, 9 Apr 2019 19:59:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E4EF728553; Tue, 9 Apr 2019 19:59:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 31DB326E98 for ; Tue, 9 Apr 2019 19:59:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726554AbfDIT7n (ORCPT ); Tue, 9 Apr 2019 15:59:43 -0400 Received: from sonic301-38.consmr.mail.ne1.yahoo.com ([66.163.184.207]:42892 "EHLO sonic301-38.consmr.mail.ne1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726530AbfDIT7n (ORCPT ); Tue, 9 Apr 2019 15:59:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1554839979; bh=dF+9lBJ8wYV5xYvHfxtglumJAG1aS1bgW4kXIJ5xz2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject; b=IPqHEB2qGbg8+cPbbpGGuzhnhnt2QOKc8Ib0BT4Vr3s467Srqfbt74NrXWSQ1dZdSI8fDbMY042O5uMq5YqzDPwrvQyhI2SDk21MwiZmloQdNfaf4o6WkN83dU40ioCTzuR+OZHuzthNiGpUpLlrG2lww7znwedrkl6E1eJBIMEiwuPWbzxt/KJScTfIDZOrqCpIkUMIbNDPNfcrkRfOBbMJpWvcIOslf+DUc5dCpx77HiXPv17g6K//5m2FpgcfFXZ5WZQRJ5zXUTwJ9rTLz460yLnDKhhlx1PC12pMkVv/r4FnbHFcC7YxhY1l1yE1DZMl54d43dICPHJRwoyXBA== X-YMail-OSG: 49YdVGwVM1ndUcJCOkRQrxdT_N_EJ9LHNbpEt5D_dVyCw0zazNfhbBAkjuWz2Ea nZucdIV7Z89FeH0PGJotoPjSTvSHYG39Q8JYsda_nLrzPXPuWTJS3tmZjLUcwhcP68pgow0Vify2 WvQtLWJJ1xLVGWzT8uWVvwXqJynY6WaqqCqCXbaBVaw_WQj2LADxqgKyKcCCEBbGSVxEVNgc2fhh XDmcrlMV_h6lh9QYG1H5kzbG_8V.24JMqOhfyEHzzDYE5RMyNRStil1cgcnSbLSSbUc8cXhENpDe rWWzuBQ63ER_7r.aeDCX3NERz925eNuElASuhGh6BPaqgEw1XjVAYCoXtnMWZ_0pxm_uFdJD4IlR oM39zWZjsZMBVult.4NxutAK9Vegxu9bSk6ebh66quiM1GltTgjEII7CXMjsqGuBbQswSV7r2YYq S9ra3YFEDq.8YqwoN6oPtKmxxn1ICj7D_04vZAulLCy3n_WNb2H9K8QZ1_7eH9KZdGlx2Vu5ERea 9p52lOPO5OY3Iy3yc3Tvrg1zZ619K7hIe1K.r3opByQijpuHxt4yr8sQnpFbeWVYbjCoqAoFE4IL .gFSUpe_Mx_eDS2wDWpJPTJNka1ydp3gdatXYdGkZHKPk2nY63MBqssusNABxBfm3023MaMoPf2h yWg1ftqTAVvMv7i4uehrIkcKoyhea7auMuxlLDuMahC_sZ.MHEXxAiSS.JQR.2.sME6Y6feQjGYi Y3z1A_OL_23YhD.8jt4.jP5WUufm.z5bVokPF2jH73HYOiuiF7d5Qp_j.CvgiK6sbRkuySjMbdG8 h_U3AHB2m8QZy1defkuB1P4QZDJqEvab3T4NmpikiIkJup735MGQR59yj2A7PRzZFXjJzkbO_iOp ONNVG_YYpzDswg1l3IO3YVBf9K2EOm3uo31fsk7rC1glpR4vpktDtCgzwQJapcGyKLrl5bDpAjSO ljOY1.5__gvkL0fCkJRvpxVTSjvmzPIAT3bmrQ0oAJG3fZKllA9dHVKMG.VwF5yw6yCWCeToeJCn TSaywmmyHzXW1GrQdz2YBGD2H9sV8ej_J4zxmBrH4.eYXAtS4GIK5rcOGRNJFOuDRoKE1feHY1fn t76CGd3S9SRrX3K7d_jJXT3L2tekrUD4ljOWBazZA1tks5moTKMfJY2gCAi0- Received: from sonic.gate.mail.ne1.yahoo.com by sonic301.consmr.mail.ne1.yahoo.com with HTTP; Tue, 9 Apr 2019 19:59:39 +0000 Received: from c-67-169-65-224.hsd1.ca.comcast.net (EHLO localhost.localdomain) ([67.169.65.224]) by smtp410.mail.bf1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 353dc739e5c49befbce16148938a824a; Tue, 09 Apr 2019 19:59:39 +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, keescook@chromium.org, john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp, paul@paul-moore.com, sds@tycho.nsa.gov Subject: [PATCH 03/59] LSM: Infrastructure management of the key security blob Date: Tue, 9 Apr 2019 12:58:28 -0700 Message-Id: <20190409195924.1509-4-casey@schaufler-ca.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20190409195924.1509-1-casey@schaufler-ca.com> References: <20190409195924.1509-1-casey@schaufler-ca.com> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Casey Schaufler Move management of the key->security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Signed-off-by: Casey Schaufler --- include/linux/lsm_hooks.h | 1 + security/security.c | 40 ++++++++++++++++++++++++++++++- security/selinux/hooks.c | 23 +++++------------- security/selinux/include/objsec.h | 7 ++++++ security/smack/smack.h | 7 ++++++ security/smack/smack_lsm.c | 33 ++++++++++++------------- 6 files changed, 75 insertions(+), 36 deletions(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 1dbed888dab0..9e3d593a1ec3 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -2058,6 +2058,7 @@ struct lsm_blob_sizes { int lbs_sock; int lbs_superblock; int lbs_ipc; + int lbs_key; int lbs_msg_msg; int lbs_task; }; diff --git a/security/security.c b/security/security.c index e32b7180282e..d05f00a40e82 100644 --- a/security/security.c +++ b/security/security.c @@ -172,6 +172,9 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) blob_sizes.lbs_inode = sizeof(struct rcu_head); lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode); lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc); +#ifdef CONFIG_KEYS + lsm_set_blob_size(&needed->lbs_key, &blob_sizes.lbs_key); +#endif lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg); lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock); lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock); @@ -307,6 +310,9 @@ static void __init ordered_lsm_init(void) init_debug("file blob size = %d\n", blob_sizes.lbs_file); init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc); +#ifdef CONFIG_KEYS + init_debug("key blob size = %d\n", blob_sizes.lbs_key); +#endif /* CONFIG_KEYS */ init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); init_debug("sock blob size = %d\n", blob_sizes.lbs_sock); init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock); @@ -573,6 +579,29 @@ static int lsm_ipc_alloc(struct kern_ipc_perm *kip) return 0; } +#ifdef CONFIG_KEYS +/** + * lsm_key_alloc - allocate a composite key blob + * @key: the key that needs a blob + * + * Allocate the key blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +int lsm_key_alloc(struct key *key) +{ + if (blob_sizes.lbs_key == 0) { + key->security = NULL; + return 0; + } + + key->security = kzalloc(blob_sizes.lbs_key, GFP_KERNEL); + if (key->security == NULL) + return -ENOMEM; + return 0; +} +#endif /* CONFIG_KEYS */ + /** * lsm_msg_msg_alloc - allocate a composite msg_msg blob * @mp: the msg_msg that needs a blob @@ -2339,12 +2368,21 @@ EXPORT_SYMBOL(security_skb_classify_flow); int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { - return call_int_hook(key_alloc, 0, key, cred, flags); + int rc = lsm_key_alloc(key); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(key_alloc, 0, key, cred, flags); + if (unlikely(rc)) + security_key_free(key); + return rc; } void security_key_free(struct key *key) { call_void_hook(key_free, key); + kfree(key->security); + key->security = NULL; } int security_key_permission(key_ref_t key_ref, diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index f38a6f484613..ee840fecfebb 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6353,11 +6353,7 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred, unsigned long flags) { const struct task_security_struct *tsec; - struct key_security_struct *ksec; - - ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); - if (!ksec) - return -ENOMEM; + struct key_security_struct *ksec = selinux_key(k); tsec = selinux_cred(cred); if (tsec->keycreate_sid) @@ -6365,18 +6361,9 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred, else ksec->sid = tsec->sid; - k->security = ksec; return 0; } -static void selinux_key_free(struct key *k) -{ - struct key_security_struct *ksec = k->security; - - k->security = NULL; - kfree(ksec); -} - static int selinux_key_permission(key_ref_t key_ref, const struct cred *cred, unsigned perm) @@ -6394,7 +6381,7 @@ static int selinux_key_permission(key_ref_t key_ref, sid = cred_sid(cred); key = key_ref_to_ptr(key_ref); - ksec = key->security; + ksec = selinux_key(key); return avc_has_perm(&selinux_state, sid, ksec->sid, SECCLASS_KEY, perm, NULL); @@ -6402,7 +6389,7 @@ static int selinux_key_permission(key_ref_t key_ref, static int selinux_key_getsecurity(struct key *key, char **_buffer) { - struct key_security_struct *ksec = key->security; + struct key_security_struct *ksec = selinux_key(key); char *context = NULL; unsigned len; int rc; @@ -6627,6 +6614,9 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = { .lbs_file = sizeof(struct file_security_struct), .lbs_inode = sizeof(struct inode_security_struct), .lbs_ipc = sizeof(struct ipc_security_struct), +#ifdef CONFIG_KEYS + .lbs_key = sizeof(struct key_security_struct), +#endif /* CONFIG_KEYS */ .lbs_msg_msg = sizeof(struct msg_security_struct), .lbs_sock = sizeof(struct sk_security_struct), .lbs_superblock = sizeof(struct superblock_security_struct), @@ -6842,7 +6832,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { #ifdef CONFIG_KEYS LSM_HOOK_INIT(key_alloc, selinux_key_alloc), - LSM_HOOK_INIT(key_free, selinux_key_free), LSM_HOOK_INIT(key_permission, selinux_key_permission), LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity), #endif diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 29f02b8f8f31..3b78aa4ee98f 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -194,6 +194,13 @@ static inline struct superblock_security_struct *selinux_superblock( return superblock->s_security + selinux_blob_sizes.lbs_superblock; } +#ifdef CONFIG_KEYS +static inline struct key_security_struct *selinux_key(const struct key *key) +{ + return key->security + selinux_blob_sizes.lbs_key; +} +#endif /* CONFIG_KEYS */ + static inline struct sk_security_struct *selinux_sock(const struct sock *sock) { return sock->sk_security + selinux_blob_sizes.lbs_sock; diff --git a/security/smack/smack.h b/security/smack/smack.h index 4ac4bf3310d7..7cc3a3382fee 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -386,6 +386,13 @@ static inline struct superblock_smack *smack_superblock( return superblock->s_security + smack_blob_sizes.lbs_superblock; } +#ifdef CONFIG_KEYS +static inline struct smack_known **smack_key(const struct key *key) +{ + return key->security + smack_blob_sizes.lbs_key; +} +#endif /* CONFIG_KEYS */ + /* * Is the directory transmuting? */ diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index fd69e1bd841b..e9560b078efe 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4179,23 +4179,13 @@ static void smack_inet_csk_clone(struct sock *sk, static int smack_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { + struct smack_known **blob = smack_key(key); struct smack_known *skp = smk_of_task(smack_cred(cred)); - key->security = skp; + *blob = skp; return 0; } -/** - * smack_key_free - Clear the key security blob - * @key: the object - * - * Clear the blob pointer - */ -static void smack_key_free(struct key *key) -{ - key->security = NULL; -} - /** * smack_key_permission - Smack access on a key * @key_ref: gets to the object @@ -4208,6 +4198,8 @@ static void smack_key_free(struct key *key) static int smack_key_permission(key_ref_t key_ref, const struct cred *cred, unsigned perm) { + struct smack_known **blob; + struct smack_known *skp; struct key *keyp; struct smk_audit_info ad; struct smack_known *tkp = smk_of_task(smack_cred(cred)); @@ -4227,7 +4219,9 @@ static int smack_key_permission(key_ref_t key_ref, * If the key hasn't been initialized give it access so that * it may do so. */ - if (keyp->security == NULL) + blob = smack_key(keyp); + skp = *blob; + if (skp == NULL) return 0; /* * This should not occur @@ -4247,8 +4241,8 @@ static int smack_key_permission(key_ref_t key_ref, request |= MAY_READ; if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR)) request |= MAY_WRITE; - rc = smk_access(tkp, keyp->security, request, &ad); - rc = smk_bu_note("key access", tkp, keyp->security, request, rc); + rc = smk_access(tkp, skp, request, &ad); + rc = smk_bu_note("key access", tkp, skp, request, rc); return rc; } @@ -4263,11 +4257,12 @@ static int smack_key_permission(key_ref_t key_ref, */ static int smack_key_getsecurity(struct key *key, char **_buffer) { - struct smack_known *skp = key->security; + struct smack_known **blob = smack_key(key); + struct smack_known *skp = *blob; size_t length; char *copy; - if (key->security == NULL) { + if (skp == NULL) { *_buffer = NULL; return 0; } @@ -4550,6 +4545,9 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { .lbs_file = sizeof(struct smack_known *), .lbs_inode = sizeof(struct inode_smack), .lbs_ipc = sizeof(struct smack_known *), +#ifdef CONFIG_KEYS + .lbs_key = sizeof(struct smack_known *), +#endif /* CONFIG_KEYS */ .lbs_msg_msg = sizeof(struct smack_known *), .lbs_sock = sizeof(struct socket_smack), .lbs_superblock = sizeof(struct superblock_smack), @@ -4671,7 +4669,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { /* key management security hooks */ #ifdef CONFIG_KEYS LSM_HOOK_INIT(key_alloc, smack_key_alloc), - LSM_HOOK_INIT(key_free, smack_key_free), LSM_HOOK_INIT(key_permission, smack_key_permission), LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity), #endif /* CONFIG_KEYS */