From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 20E2AC3F68F for ; Tue, 24 Dec 2019 23:21:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E947B206D7 for ; Tue, 24 Dec 2019 23:21:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=yahoo.com header.i=@yahoo.com header.b="Soop2AsC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726317AbfLXXV4 (ORCPT ); Tue, 24 Dec 2019 18:21:56 -0500 Received: from sonic313-15.consmr.mail.ne1.yahoo.com ([66.163.185.38]:33700 "EHLO sonic313-15.consmr.mail.ne1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726258AbfLXXV4 (ORCPT ); Tue, 24 Dec 2019 18:21:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1577229714; bh=pk4OM2anm1/C+LQ96dtDYWeHAfHr5wLruGqEfoA0KyY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject; b=Soop2AsCLpM2Sz1G/DOJFxeQtG7xoPAtmQMygo31DkEmsQNv0S/w16dbWRw8ROIzk1/AWYBRrokZbQMthAl/bVWFYm7E+yMyBIyTQRnMCr2IhF1ADvUtFIrDnrUSlnM/95umQguqbXDC+61jwcduzhMp3+qpIXQIGNDry3Vqq3XlI5xrdDjAJGGHp1t9Q66g/B58LePwUo5Tobpu84yogfJDYYwdKVmO8fx1SB9S2N5HWEbiX+lC2iSobUbEtEbMt4yaK1pQv+9fwLwTDOpe6j25al1mJ80u2KNQOl4mL0HU/FzB2w2ATLMINbXNIcNULsS1JcNPARK0fXtldt7+rw== X-YMail-OSG: o2124OUVM1kAI69F7iz8kRrKz6cPerXqjDrr0l.EfnBQwAs_3frsTOfx_8xhD6. fnGYaz4mAtHS8f7XDJNETrWyQh9.WRpkq_8Xf63Usyd0KGLMNpPC5rZIGeIpAQNgvNvOnQzNIzyT .v_OHDc8GQMTcYxCjV3WVpLV2KrcExNqP3DBiWqQeODhnoeOSOiK3MSCD_HDPRjPcKfePuw3X3B8 Op8ALuDg3VaqspBypbiFlB2sqBVQ4qlOXkoH.BcfVbMyPDpQYkgMgnMkSvPFi5xlszq3aBVUdkwI 5DTweybYQnByh3eyvYpNNWk7LUQLItKYSuOeXO0G.RoIVp7WAK3ZRVu0JiamK.bJ7AIoVlypp9Om rI8WeJfSkZRFZ5ke61bfEI6.ZFpbTzp9nu4gBcaFSnJ.DC1Bf7pU2cKnj74y7QS0nW6SeHxbkUOA OTiBmhLWYSX2C1atPiBJuozyeVwxKopq3STrt80XspX69grCQ3nHeMlfx20r3dAunRU0uQlxJ1uH CozQJrcdRjjim4zMxKkKvROlofHqJ5ue.YjAO4BmOX.MDj.MolPMxN1YLU6qOJzIrSkpTQa7JT8m yYyKZUbhZ.l3k2WEWaVPe.tl3qFPg6afwn3jwWdeodg0PbsvWbUhAdvTm1d0MJttJ7.g.ldl.B4d mPlMtGXT0zRAT0zlxm5mSCoWC5jrPXAQvrm8kzAapMvNfhybma401kJi9rSZx7PyNtz0IylQC4Dd OdUxc19DLHhJ7FDV.Jzq587ygA6kUwbBCIizzvY2b2CVDdPTdeeq16NKIlU6XWarqfrae7eyKUxb T7q8RNFxrldBv7YsOtAlRod4HMf581pc7lhYnj7f4iheQDUggLMlbqPLWhCwA4TYhYYz0NDACdPG 3xmBSxXIE76qSsF0xC8oRxLKtypPRlwRe.Pc8DOaMrLkzSbz62il7Kr_DCQyM5WZnbhilB5Xjlrb NpySok.VrRwnXgJweOpT6Yh.icWrqzN6Uirwea8ltyCLdPhHggu8NQC2lX91PG0bAua8RMi30rZ4 Ln.t3Yiag6tza.3hIcTJfgFzY9_gUiHqeBsREz34XEWNnJpIpkFMXEmtAelRrs10I4Da8qnqNkCP HTRpVqTWDszT.EtQZtOT9BZZDvkElY64w9K8NaYntMqY6CwnrSnCtN0W2FynxJTIX1NeAG9mtlZi 92JiUYcBRHLuspX9pBCgmSBim5XaUUWTTwPAp63qt9YHKQIa1rGVR71MnM2pPllK9MTl76KU1033 oJO_fWFizxZsQl.bAlU8bOcqt5jM20s1ndLKhAWAJyKd9zW.hPw0Eor1oNDlKi.uPT5U6hezXyY9 le2nuXajoumWXd14WiWZoMtw6KR6aHiT83D7Hu3Crag2zhRAi5HwNgNvHKs21GiaC.yL9wbwA1.. ge.UQQiGud_W2dSVMtEY1tHTQbkI6DCobTfCckFNb60aUTSW6HpqMt0eFGeaxNfr.IP9lnjduf4_ x Received: from sonic.gate.mail.ne1.yahoo.com by sonic313.consmr.mail.ne1.yahoo.com with HTTP; Tue, 24 Dec 2019 23:21:54 +0000 Received: by smtp416.mail.bf1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID cbb1f47b4aa1c76f1688d5d651e30c9e; Tue, 24 Dec 2019 23:21:53 +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 v12 16/25] LSM: Use lsmcontext in security_dentry_init_security Date: Tue, 24 Dec 2019 15:19:06 -0800 Message-Id: <20191224231915.7208-17-casey@schaufler-ca.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191224231915.7208-1-casey@schaufler-ca.com> References: <20191224231915.7208-1-casey@schaufler-ca.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Change the security_dentry_init_security() interface to fill an lsmcontext structure instead of a void * data area and a length. The lone caller of this interface is NFS4, which may make copies of the data using its own mechanisms. A rework of the nfs4 code to use the lsmcontext properly is a significant project, so the coward's way out is taken, and the lsmcontext data from security_dentry_init_security() is copied, then released directly. This interface does not use the "display". There is currently not case where that is useful or reasonable. Reviewed-by: Kees Cook Reviewed-by: John Johansen Signed-off-by: Casey Schaufler --- fs/nfs/nfs4proc.c | 26 ++++++++++++++++---------- include/linux/security.h | 7 +++---- security/security.c | 29 +++++++++++++++++++++++++---- 3 files changed, 44 insertions(+), 18 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index a30e36654c57..78d63f7f0088 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -112,6 +112,7 @@ static inline struct nfs4_label * nfs4_label_init_security(struct inode *dir, struct dentry *dentry, struct iattr *sattr, struct nfs4_label *label) { + struct lsmcontext context; int err; if (label == NULL) @@ -121,21 +122,26 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry, return NULL; err = security_dentry_init_security(dentry, sattr->ia_mode, - &dentry->d_name, (void **)&label->label, &label->len); - if (err == 0) - return label; + &dentry->d_name, &context); + + if (err) + return NULL; + + label->label = kmemdup(context.context, context.len, GFP_KERNEL); + if (label->label == NULL) + label = NULL; + else + label->len = context.len; + + security_release_secctx(&context); + + return label; - return NULL; } static inline void nfs4_label_release_security(struct nfs4_label *label) { - struct lsmcontext scaff; /* scaffolding */ - - if (label) { - lsmcontext_init(&scaff, label->label, label->len, 0); - security_release_secctx(&scaff); - } + kfree(label->label); } static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label) { diff --git a/include/linux/security.h b/include/linux/security.h index 00421941f683..a5eba06a9382 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -398,8 +398,8 @@ int security_add_mnt_opt(const char *option, const char *val, int len, void **mnt_opts); int security_move_mount(const struct path *from_path, const struct path *to_path); int security_dentry_init_security(struct dentry *dentry, int mode, - const struct qstr *name, void **ctx, - u32 *ctxlen); + const struct qstr *name, + struct lsmcontext *ctx); int security_dentry_create_files_as(struct dentry *dentry, int mode, struct qstr *name, const struct cred *old, @@ -790,8 +790,7 @@ static inline void security_inode_free(struct inode *inode) static inline int security_dentry_init_security(struct dentry *dentry, int mode, const struct qstr *name, - void **ctx, - u32 *ctxlen) + struct lsmcontext *ctx) { return -EOPNOTSUPP; } diff --git a/security/security.c b/security/security.c index 4ba1a6ed36e0..8aa107b57af9 100644 --- a/security/security.c +++ b/security/security.c @@ -1011,12 +1011,33 @@ void security_inode_free(struct inode *inode) inode_free_by_rcu); } +/* + * security_dentry_init_security - initial context for a dentry + * @dentry: directory entry + * @mode: access mode + * @name: path name + * @context: resulting security context + * + * Use at most one security module to get the initial + * security context. Do not use the "display". + * + * Returns -EOPNOTSUPP if not supplied by any module or the module result. + */ int security_dentry_init_security(struct dentry *dentry, int mode, - const struct qstr *name, void **ctx, - u32 *ctxlen) + const struct qstr *name, + struct lsmcontext *cp) { - return call_int_hook(dentry_init_security, -EOPNOTSUPP, dentry, mode, - name, ctx, ctxlen); + struct security_hook_list *hp; + + hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security, + list) { + cp->slot = hp->lsmid->slot; + return hp->hook.dentry_init_security(dentry, mode, name, + (void **)&cp->context, + &cp->len); + } + + return -EOPNOTSUPP; } EXPORT_SYMBOL(security_dentry_init_security); -- 2.20.1