From patchwork Tue Mar 3 22:58:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Mayhew X-Patchwork-Id: 11418883 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A6ABF14E3 for ; Tue, 3 Mar 2020 22:58:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D47E20870 for ; Tue, 3 Mar 2020 22:58:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Rx21Z/ND" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728137AbgCCW6q (ORCPT ); Tue, 3 Mar 2020 17:58:46 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:49697 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726766AbgCCW6q (ORCPT ); Tue, 3 Mar 2020 17:58:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583276324; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=41cmoi2WBuoRJfhZcXC21IKnpzNXQPaxD3gBuaHiCh0=; b=Rx21Z/NDbTx1anErM4QPhvfhUfPQfTobFpJR8fWD5iITVWGa0PszqrDYmhuYaMEmgIZmmS AuUNWqb/euaJlkvjPjR5Nrg0awt9Nmo/StRqHMyUoaYuBHba2YoE50WaMrL78BWx4zSOj7 3DiptBxyaCJfMsmxdTYHx41/SWJ1g3g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-460-PBJiAyt6O2KcwrH-kJJT8g-1; Tue, 03 Mar 2020 17:58:40 -0500 X-MC-Unique: PBJiAyt6O2KcwrH-kJJT8g-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EFE66DB60; Tue, 3 Mar 2020 22:58:38 +0000 (UTC) Received: from aion.usersys.redhat.com (ovpn-123-59.rdu2.redhat.com [10.10.123.59]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3473089A9C; Tue, 3 Mar 2020 22:58:38 +0000 (UTC) Received: by aion.usersys.redhat.com (Postfix, from userid 1000) id 7588A1A0107; Tue, 3 Mar 2020 17:58:37 -0500 (EST) From: Scott Mayhew To: trond.myklebust@hammerspace.com, anna.schumaker@netapp.com Cc: richard_c_haines@btinternet.com, bfields@fieldses.org, paul@paul-moore.com, sds@tycho.nsa.gov, linux-nfs@vger.kernel.org, selinux@vger.kernel.org Subject: [PATCH] NFS: Ensure security label is set for root inode Date: Tue, 3 Mar 2020 17:58:37 -0500 Message-Id: <20200303225837.1557210-1-smayhew@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Sender: selinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org When using NFSv4.2, the security label for the root inode should be set via a call to nfs_setsecurity() during the mount process, otherwise the inode will appear as unlabeled for up to acdirmin seconds. Currently the label for the root inode is allocated, retrieved, and freed entirely witin nfs4_proc_get_root(). Add a field for the label to the nfs_fattr struct, and allocate & free the label in nfs_get_root(), where we also add a call to nfs_setsecurity(). Note that for the call to nfs_setsecurity() to succeed, it's necessary to also move the logic calling security_sb_{set,clone}_security() from nfs_get_tree_common() down into nfs_get_root()... otherwise the SBLABEL_MNT flag will not be set in the super_block's security flags and nfs_setsecurity() will silently fail. Reported-by: Richard Haines Signed-off-by: Scott Mayhew Acked-by: Stephen Smalley Tested-by: Stephen Smalley --- fs/nfs/getroot.c | 39 +++++++++++++++++++++++++++++++++++---- fs/nfs/nfs4proc.c | 12 +++--------- fs/nfs/super.c | 25 ------------------------- include/linux/nfs_xdr.h | 1 + 4 files changed, 39 insertions(+), 38 deletions(-) diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index b012c2668a1f..6d0628149390 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -73,6 +73,7 @@ int nfs_get_root(struct super_block *s, struct fs_context *fc) struct inode *inode; char *name; int error = -ENOMEM; + unsigned long kflags = 0, kflags_out = 0; name = kstrdup(fc->source, GFP_KERNEL); if (!name) @@ -83,11 +84,14 @@ int nfs_get_root(struct super_block *s, struct fs_context *fc) if (fsinfo.fattr == NULL) goto out_name; + fsinfo.fattr->label = nfs4_label_alloc(server, GFP_KERNEL); + if (IS_ERR(fsinfo.fattr->label)) + goto out_fattr; error = server->nfs_client->rpc_ops->getroot(server, ctx->mntfh, &fsinfo); if (error < 0) { dprintk("nfs_get_root: getattr error = %d\n", -error); nfs_errorf(fc, "NFS: Couldn't getattr on root"); - goto out_fattr; + goto out_label; } inode = nfs_fhget(s, ctx->mntfh, fsinfo.fattr, NULL); @@ -95,12 +99,12 @@ int nfs_get_root(struct super_block *s, struct fs_context *fc) dprintk("nfs_get_root: get root inode failed\n"); error = PTR_ERR(inode); nfs_errorf(fc, "NFS: Couldn't get root inode"); - goto out_fattr; + goto out_label; } error = nfs_superblock_set_dummy_root(s, inode); if (error != 0) - goto out_fattr; + goto out_label; /* root dentries normally start off anonymous and get spliced in later * if the dentry tree reaches them; however if the dentry already @@ -111,7 +115,7 @@ int nfs_get_root(struct super_block *s, struct fs_context *fc) dprintk("nfs_get_root: get root dentry failed\n"); error = PTR_ERR(root); nfs_errorf(fc, "NFS: Couldn't get root dentry"); - goto out_fattr; + goto out_label; } security_d_instantiate(root, inode); @@ -123,12 +127,39 @@ int nfs_get_root(struct super_block *s, struct fs_context *fc) } spin_unlock(&root->d_lock); fc->root = root; + if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL) + kflags |= SECURITY_LSM_NATIVE_LABELS; + if (ctx->clone_data.sb) { + if (d_inode(fc->root)->i_fop != &nfs_dir_operations) { + error = -ESTALE; + goto error_splat_root; + } + /* clone any lsm security options from the parent to the new sb */ + error = security_sb_clone_mnt_opts(ctx->clone_data.sb, s, kflags, + &kflags_out); + } else { + error = security_sb_set_mnt_opts(s, fc->security, + kflags, &kflags_out); + } + if (error) + goto error_splat_root; + if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL && + !(kflags_out & SECURITY_LSM_NATIVE_LABELS)) + NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL; + + nfs_setsecurity(inode, fsinfo.fattr, fsinfo.fattr->label); error = 0; +out_label: + nfs4_label_free(fsinfo.fattr->label); out_fattr: nfs_free_fattr(fsinfo.fattr); out_name: kfree(name); out: return error; +error_splat_root: + dput(fc->root); + fc->root = NULL; + goto out_label; } diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 69b7ab7a5815..cb34e840e4fb 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4002,7 +4002,7 @@ static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *mntfh, { int error; struct nfs_fattr *fattr = info->fattr; - struct nfs4_label *label = NULL; + struct nfs4_label *label = fattr->label; error = nfs4_server_capabilities(server, mntfh); if (error < 0) { @@ -4010,23 +4010,17 @@ static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *mntfh, return error; } - label = nfs4_label_alloc(server, GFP_KERNEL); - if (IS_ERR(label)) - return PTR_ERR(label); - error = nfs4_proc_getattr(server, mntfh, fattr, label, NULL); if (error < 0) { dprintk("nfs4_get_root: getattr error = %d\n", -error); - goto err_free_label; + goto out; } if (fattr->valid & NFS_ATTR_FATTR_FSID && !nfs_fsid_equal(&server->fsid, &fattr->fsid)) memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid)); -err_free_label: - nfs4_label_free(label); - +out: return error; } diff --git a/fs/nfs/super.c b/fs/nfs/super.c index dada09b391c6..bb14bede6da5 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1179,7 +1179,6 @@ int nfs_get_tree_common(struct fs_context *fc) struct super_block *s; int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super; struct nfs_server *server = ctx->server; - unsigned long kflags = 0, kflags_out = 0; int error; ctx->server = NULL; @@ -1239,26 +1238,6 @@ int nfs_get_tree_common(struct fs_context *fc) goto error_splat_super; } - if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL) - kflags |= SECURITY_LSM_NATIVE_LABELS; - if (ctx->clone_data.sb) { - if (d_inode(fc->root)->i_fop != &nfs_dir_operations) { - error = -ESTALE; - goto error_splat_root; - } - /* clone any lsm security options from the parent to the new sb */ - error = security_sb_clone_mnt_opts(ctx->clone_data.sb, s, kflags, - &kflags_out); - } else { - error = security_sb_set_mnt_opts(s, fc->security, - kflags, &kflags_out); - } - if (error) - goto error_splat_root; - if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL && - !(kflags_out & SECURITY_LSM_NATIVE_LABELS)) - NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL; - s->s_flags |= SB_ACTIVE; error = 0; @@ -1268,10 +1247,6 @@ int nfs_get_tree_common(struct fs_context *fc) out_err_nosb: nfs_free_server(server); goto out; - -error_splat_root: - dput(fc->root); - fc->root = NULL; error_splat_super: deactivate_locked_super(s); goto out; diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 94c77ed55ce1..6838c149f335 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -75,6 +75,7 @@ struct nfs_fattr { struct nfs4_string *owner_name; struct nfs4_string *group_name; struct nfs4_threshold *mdsthreshold; /* pNFS threshold hints */ + struct nfs4_label *label; }; #define NFS_ATTR_FATTR_TYPE (1U << 0)