From patchwork Wed Jul 3 21:25:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Casey Schaufler X-Patchwork-Id: 11030443 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 6EA9414DB for ; Wed, 3 Jul 2019 21:26:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 62D10289F7 for ; Wed, 3 Jul 2019 21:26:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 578F5289FF; Wed, 3 Jul 2019 21:26:32 +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 BF05B289F7 for ; Wed, 3 Jul 2019 21:26:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727338AbfGCV0b (ORCPT ); Wed, 3 Jul 2019 17:26:31 -0400 Received: from sonic314-27.consmr.mail.ne1.yahoo.com ([66.163.189.153]:35146 "EHLO sonic314-27.consmr.mail.ne1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727341AbfGCV0a (ORCPT ); Wed, 3 Jul 2019 17:26:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1562189188; bh=aGyFxBCKVDPk80ns0DK3ZdP2nGMKgpbcCOrX7VDI3ak=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From:Subject; b=EtcDEVGX5da3y9JLvjYWbRunmt0oq8RsYfglLUHl5YIZNomoaAAqSUzweZ+VCfeXyxL3V7Zd53s26omDh5goMenQQ6V5nkLh8o3vDDpY2hfzePfr09MEVRXh2daZOwKjP0GC5mXOxzVQNrfCWb+iGe7g6kd/kXfrWjRIE6+NXCj0s3Y6OpiU0HJY5ZDHht2rAsqk7/KpjVs9H3JPqVTLXHUk+cOKNlCTlgnYS61LG7p+lJKBBuutZzlJK8EKpJbKyBeqwYbAuTmyS4DeT6jJdxiDBjyOFPkRy3/Ty+k075epgsRb5nA/XxbAdUpGO4H2nU+1j0W+3XSxaoyVnR6tWA== X-YMail-OSG: Qk8umIkVM1nU9XffwYug0tiu6ij9TMUxJROdcHruJmgn5GzCeMCWYu3C1CrWSwV YQI3YvGAWrCq4JxATESfWHsJ4FTGhuFx4Nynhnrm3YUVogYM5xhGAJdhU_94Zah9zw5CRb.LBIUz 36Fmjy56G1A_yWuCZckq6ur7NKy4LAXexzJCa6ihGHTA2wNZrMlIYeb4t7k_3NFwDxM9FQfAds.d sLTom8csecr4I0nYjGJIlxgc41VLhUtEA_6WPyi5fkx3VhoJP9sZ5dTZlrjWEQW5OWVAvlYyCkBu J0V3pUjx.F9QoCsIq2Bl9UWAWyd36s02EY.4aYjT1dbZjH5ZUiKpQv1SZSN1q.zYnUYFErOju9CD XvOQOz1QsJn_dVTr1Am9nUeEWu5NP3i2gYc_zXyfyAgGaryeafFxg7wsL19dnPesvijnpiF3Y3uN Aw0.Oc4W85dOr65AGWBQ81lAJc3FGQ37_dbQsDNt5NZ0R.Xq4B6CfznYQZ.8Hyb7MPUGzATGcVEJ frZfrAV_M__0RKuj71yrAdhZkmmK6Jr5Kw.vYoAxheIPTvro2stVlvLFCuSZo0Bdr7BC7AO3Wdb9 DTeWlsmQyAAYUntHQWk66jFEne6DdEozjk7hXSaiuAcnPjLrjrCJqe_5gTTYDEXCMz_Z01O.2x7V _.oz1CVh_In_MCqldJ0tVMB0geuOZY8wPQbO01CLZPuhArjIQUAD2aYg9Sz_3RW38t14ctd1IXH1 SCBQxuwCc4bhIbb3Pm4sB3AQr5dhUkAPSr6UlEEmC6OHd3jljCMepFwWXoBgwbGfScYxqOUBy1uO 2.TlENbW91Lz_p1ZQ9OwtkOjvpz7u4FVixL0Y1GejcBbHpbG2DvzMwtFE7BoAiwztKy01499JXeb yR0AHnyO9tWrq8o74lkcHK5qRJTLsmx53iBJWq25jIVUEv7h4KsvOviIOmGcLb9mQzv080WNG46O 6LCjmlpZwRUAHZX32QHAebYMvsCaGS3XLbn7XVpVyYFDVtGKIkvJ_XrjJyTBrdDmZWgFlvilim6g rxUWM1v0UIzuutXOlKadKe9PJp_DJlMh3.hTmqs2XDejJU5n6pmqfRMtmA4AKQakZzdB6gTzYbVL VeU9iNdKghZ6gx7jbXaPGbOykACl36i8vE.70JLT9OQOz9PlnrFXLggN94kTUtHV_bO4WIHPOmvR 5.0RlwkspR34BALJQiU9DFkqmj4NVrGOZr.G.p9c.1I_6TjxdAAcUo7.FsqP8.fznc4Q_j7dKZDZ eXJ40A3d7.kGTnwXLbnPYFpMFwGVngEEzLpsk.PzMLMcvp7b5 Received: from sonic.gate.mail.ne1.yahoo.com by sonic314.consmr.mail.ne1.yahoo.com with HTTP; Wed, 3 Jul 2019 21:26:28 +0000 Received: by smtp420.mail.ne1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 2c078f1d0732da9907514b19d300052b; Wed, 03 Jul 2019 21:26:22 +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 v5 19/23] LSM: Use lsmcontext in security_inode_getsecctx Date: Wed, 3 Jul 2019 14:25:34 -0700 Message-Id: <20190703212538.7383-20-casey@schaufler-ca.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190703212538.7383-1-casey@schaufler-ca.com> References: <20190703212538.7383-1-casey@schaufler-ca.com> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Change the security_inode_getsecctx() interface to fill a lsmcontext structure instead of data and length pointers. This provides the information about which LSM created the context so that security_release_secctx() can use the correct hook. A lsmcontext is used within kernfs to store the security information as well. security_inode_getsecctx() does not use the "display" value. There's only one possible user at any time at this point, and the use is only internal. Signed-off-by: Casey Schaufler Reviewed-by: Kees Cook --- fs/kernfs/dir.c | 9 ++------- fs/kernfs/inode.c | 34 ++++++++++++---------------------- fs/kernfs/kernfs-internal.h | 3 +-- fs/nfsd/nfs4xdr.c | 23 +++++++++-------------- include/linux/security.h | 5 +++-- security/security.c | 13 +++++++++++-- 6 files changed, 38 insertions(+), 49 deletions(-) diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index c8362b6d556e..1d000289d8b7 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -532,13 +532,8 @@ void kernfs_put(struct kernfs_node *kn) kfree_const(kn->name); if (kn->iattr) { - struct lsmcontext scaff; /* scaffolding */ - - if (kn->iattr->ia_secdata) { - lsmcontext_init(&scaff, kn->iattr->ia_secdata, - kn->iattr->ia_secdata_len, 0); - security_release_secctx(&scaff); - } + if (kn->iattr->ia_context.context) + security_release_secctx(&kn->iattr->ia_context); simple_xattrs_free(&kn->iattr->xattrs); kmem_cache_free(kernfs_iattrs_cache, kn->iattr); } diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index 02cde9dac5ee..ffbf7863306d 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -135,21 +135,14 @@ int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr) return error; } -static int kernfs_node_setsecdata(struct kernfs_iattrs *attrs, void **secdata, - u32 *secdata_len) +static void kernfs_node_setsecdata(struct kernfs_iattrs *attrs, + struct lsmcontext *cp) { - void *old_secdata; - size_t old_secdata_len; + struct lsmcontext old_context; - old_secdata = attrs->ia_secdata; - old_secdata_len = attrs->ia_secdata_len; - - attrs->ia_secdata = *secdata; - attrs->ia_secdata_len = *secdata_len; - - *secdata = old_secdata; - *secdata_len = old_secdata_len; - return 0; + old_context = attrs->ia_context; + attrs->ia_context = *cp; + *cp = old_context; } ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size) @@ -192,8 +185,8 @@ static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode) * persistent copy in kernfs_node. */ set_inode_attr(inode, &attrs->ia_iattr); - security_inode_notifysecctx(inode, attrs->ia_secdata, - attrs->ia_secdata_len); + security_inode_notifysecctx(inode, attrs->ia_context.context, + attrs->ia_context.len); } if (kernfs_type(kn) == KERNFS_DIR) @@ -350,8 +343,6 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler, struct kernfs_node *kn = inode->i_private; struct kernfs_iattrs *attrs; struct lsmcontext context; - void *secdata; - u32 secdata_len = 0; int error; attrs = kernfs_iattrs(kn); @@ -361,18 +352,17 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler, error = security_inode_setsecurity(inode, suffix, value, size, flags); if (error) return error; - error = security_inode_getsecctx(inode, &secdata, &secdata_len); + error = security_inode_getsecctx(inode, &context); if (error) return error; mutex_lock(&kernfs_mutex); - error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len); + kernfs_node_setsecdata(attrs, &context); mutex_unlock(&kernfs_mutex); - if (secdata) { - lsmcontext_init(&context, secdata, secdata_len, 0); + if (context.context) security_release_secctx(&context); - } + return error; } diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 0b7d197a904c..844a028d282f 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -21,8 +21,7 @@ struct kernfs_iattrs { struct iattr ia_iattr; - void *ia_secdata; - u32 ia_secdata_len; + struct lsmcontext ia_context; struct simple_xattrs xattrs; }; diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index bb3db033e144..d2dbec9c3340 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2304,11 +2304,11 @@ nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types) #ifdef CONFIG_NFSD_V4_SECURITY_LABEL static inline __be32 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp, - void *context, int len) + struct lsmcontext *context) { __be32 *p; - p = xdr_reserve_space(xdr, len + 4 + 4 + 4); + p = xdr_reserve_space(xdr, context->len + 4 + 4 + 4); if (!p) return nfserr_resource; @@ -2318,13 +2318,13 @@ nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp, */ *p++ = cpu_to_be32(0); /* lfs */ *p++ = cpu_to_be32(0); /* pi */ - p = xdr_encode_opaque(p, context, len); + p = xdr_encode_opaque(p, context->context, context->len); return 0; } #else static inline __be32 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp, - void *context, int len) + struct lsmcontext *context) { return 0; } #endif @@ -2420,9 +2420,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, __be32 status; int err; struct nfs4_acl *acl = NULL; - struct lsmcontext scaff; /* scaffolding */ - void *context = NULL; - int contextlen; + struct lsmcontext context = { }; bool contextsupport = false; struct nfsd4_compoundres *resp = rqstp->rq_resp; u32 minorversion = resp->cstate.minorversion; @@ -2479,7 +2477,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) { if (exp->ex_flags & NFSEXP_SECURITY_LABEL) err = security_inode_getsecctx(d_inode(dentry), - &context, &contextlen); + &context); else err = -EOPNOTSUPP; contextsupport = (err == 0); @@ -2908,8 +2906,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, } if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) { - status = nfsd4_encode_security_label(xdr, rqstp, context, - contextlen); + status = nfsd4_encode_security_label(xdr, rqstp, &context); if (status) goto out; } @@ -2920,10 +2917,8 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, out: #ifdef CONFIG_NFSD_V4_SECURITY_LABEL - if (context) { - lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/ - security_release_secctx(&scaff); - } + if (context.context) + security_release_secctx(&context); #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */ kfree(acl); if (tempfh) { diff --git a/include/linux/security.h b/include/linux/security.h index 2674eb70c2d7..c16aea55be97 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -489,7 +489,7 @@ void security_release_secctx(struct lsmcontext *cp); void security_inode_invalidate_secctx(struct inode *inode); int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); +int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp); #else /* CONFIG_SECURITY */ static inline int call_lsm_notifier(enum lsm_event event, void *data) @@ -1290,7 +1290,8 @@ static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 { return -EOPNOTSUPP; } -static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +static inline int security_inode_getsecctx(struct inode *inode, + struct lsmcontext *cp) { return -EOPNOTSUPP; } diff --git a/security/security.c b/security/security.c index 54d7e7f02a8b..7c1c50ac2278 100644 --- a/security/security.c +++ b/security/security.c @@ -2179,9 +2179,18 @@ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) } EXPORT_SYMBOL(security_inode_setsecctx); -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp) { - return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen); + struct security_hook_list *hp; + + memset(cp, 0, sizeof(*cp)); + + hlist_for_each_entry(hp, &security_hook_heads.inode_getsecctx, list) { + cp->slot = hp->lsmid->slot; + return hp->hook.inode_getsecctx(inode, (void **)&cp->context, + &cp->len); + } + return -EOPNOTSUPP; } EXPORT_SYMBOL(security_inode_getsecctx);