From patchwork Thu Mar 25 19:37:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miklos Szeredi X-Patchwork-Id: 12164931 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 0B533C433E6 for ; Thu, 25 Mar 2021 19:39:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E084861A50 for ; Thu, 25 Mar 2021 19:39:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230374AbhCYTim (ORCPT ); Thu, 25 Mar 2021 15:38:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:33414 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230238AbhCYTiH (ORCPT ); Thu, 25 Mar 2021 15:38:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616701086; 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: in-reply-to:in-reply-to:references:references; bh=Ta4CkjG/mjBUKrafZ3vedGcl5jpoCWT94WasqZXc5to=; b=jGhm+ckwyLuHZQxn2/Z6jgf1vfAgusL8nxP8VoVbghDHN0EiH6u2W4Rg/2BUzCrhWPkARO IwYart0Bs5+gKHA3yx6iY4jpI7qYEU8hAKLsufFGLcaDBLzgU7rfv76b7k7qKGV3YPPNh0 J+cIfu2jZOHw3WcJ3vE0AnV0e1JZjlA= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-210-YDhukK9YOMiwVGmjN4aPnw-1; Thu, 25 Mar 2021 15:38:03 -0400 X-MC-Unique: YDhukK9YOMiwVGmjN4aPnw-1 Received: by mail-ed1-f72.google.com with SMTP id r19so3211458edv.3 for ; Thu, 25 Mar 2021 12:38:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Ta4CkjG/mjBUKrafZ3vedGcl5jpoCWT94WasqZXc5to=; b=rfy39y1YXr6EW6TpilRjv1sSLdRJZd57cSYwCgfPxJshlnPL7toINeBQmljuCDNfGB HcRB+MZnb/JultGMIyNd98Voxb7eXsdRsdj512+AJk26gl9QwWr5EjNd0z1LzXAFV22l CocrHk6H75RsYmPW+1mOsUYJ6/Cb7JL957cIkMtALdcOAwqQq5N3UlaqsTI+1GnAz/lT ai/S8fcNDkRGxEyWGOjQUedggb9M3oiXZi5RSEKnTROEew6GNOQp62/QuEJ3c4oH1vyQ Fpy1kUsO8fJioVEVrIBZQ4eR84DCKL6lnOAmxFn3ypKnORmsZ2CZb2tDQLs7ToiJLYRo 46oA== X-Gm-Message-State: AOAM533PxxB1JnKAZZ6b+cLwMRjOTQg0crEnrjiqGwuJJ7jlpYY5x2Nl Uv+0ffsbfUPwRngddc/PWV+aizuXn293D+okXWjaTXtVt+X44DtU7bpi0DqiRQb5+BS/W7NWQxx qYHRgEFMpZaKAEAcHJ03Vqs3OBa+X6eyYwKJXskrJJTddsAdru/QKP4+05BJpBJIqdwcwExLYdC dj4A== X-Received: by 2002:aa7:d316:: with SMTP id p22mr10582781edq.107.1616701080873; Thu, 25 Mar 2021 12:38:00 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyZM843u5auKWMZBpd55b9eAYbS8hUYpb57eYIrIuZev0PFdRIh4WsfVqKshHFAeVf2GnnI8Q== X-Received: by 2002:aa7:d316:: with SMTP id p22mr10582757edq.107.1616701080612; Thu, 25 Mar 2021 12:38:00 -0700 (PDT) Received: from miu.piliscsaba.redhat.com (catv-86-101-169-67.catv.broadband.hu. [86.101.169.67]) by smtp.gmail.com with ESMTPSA id si7sm2881996ejb.84.2021.03.25.12.37.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Mar 2021 12:38:00 -0700 (PDT) From: Miklos Szeredi To: linux-fsdevel@vger.kernel.org Cc: Al Viro , linux-kernel@vger.kernel.org Subject: [PATCH v3 03/18] ovl: stack fileattr ops Date: Thu, 25 Mar 2021 20:37:40 +0100 Message-Id: <20210325193755.294925-4-mszeredi@redhat.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210325193755.294925-1-mszeredi@redhat.com> References: <20210325193755.294925-1-mszeredi@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add stacking for the fileattr operations. Add hack for calling security_file_ioctl() for now. Probably better to have a pair of specific hooks for these operations. Signed-off-by: Miklos Szeredi --- fs/overlayfs/dir.c | 2 ++ fs/overlayfs/inode.c | 77 ++++++++++++++++++++++++++++++++++++++++ fs/overlayfs/overlayfs.h | 3 ++ 3 files changed, 82 insertions(+) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 836f14b9d3a6..93efe7048a77 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -1301,4 +1301,6 @@ const struct inode_operations ovl_dir_inode_operations = { .listxattr = ovl_listxattr, .get_acl = ovl_get_acl, .update_time = ovl_update_time, + .fileattr_get = ovl_fileattr_get, + .fileattr_set = ovl_fileattr_set, }; diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 003cf83bf78a..c3c96b4b3b33 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -11,6 +11,8 @@ #include #include #include +#include +#include #include "overlayfs.h" @@ -500,6 +502,79 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, return err; } +/* + * Work around the fact that security_file_ioctl() takes a file argument. + * Introducing security_inode_fileattr_get/set() hooks would solve this issue + * properly. + */ +static int ovl_security_fileattr(struct dentry *dentry, struct fileattr *fa, + bool set) +{ + struct path realpath; + struct file *file; + unsigned int cmd; + int err; + + ovl_path_real(dentry, &realpath); + file = dentry_open(&realpath, O_RDONLY, current_cred()); + if (IS_ERR(file)) + return PTR_ERR(file); + + if (set) + cmd = fa->fsx_valid ? FS_IOC_FSSETXATTR : FS_IOC_SETFLAGS; + else + cmd = fa->fsx_valid ? FS_IOC_FSGETXATTR : FS_IOC_GETFLAGS; + + err = security_file_ioctl(file, cmd, 0); + fput(file); + + return err; +} + +int ovl_fileattr_set(struct user_namespace *mnt_userns, + struct dentry *dentry, struct fileattr *fa) +{ + struct inode *inode = d_inode(dentry); + struct dentry *upperdentry; + const struct cred *old_cred; + int err; + + err = ovl_want_write(dentry); + if (err) + goto out; + + err = ovl_copy_up(dentry); + if (!err) { + upperdentry = ovl_dentry_upper(dentry); + + old_cred = ovl_override_creds(inode->i_sb); + err = ovl_security_fileattr(dentry, fa, true); + if (!err) + err = vfs_fileattr_set(&init_user_ns, upperdentry, fa); + revert_creds(old_cred); + ovl_copyflags(ovl_inode_real(inode), inode); + } + ovl_drop_write(dentry); +out: + return err; +} + +int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa) +{ + struct inode *inode = d_inode(dentry); + struct dentry *realdentry = ovl_dentry_real(dentry); + const struct cred *old_cred; + int err; + + old_cred = ovl_override_creds(inode->i_sb); + err = ovl_security_fileattr(dentry, fa, false); + if (!err) + err = vfs_fileattr_get(realdentry, fa); + revert_creds(old_cred); + + return err; +} + static const struct inode_operations ovl_file_inode_operations = { .setattr = ovl_setattr, .permission = ovl_permission, @@ -508,6 +583,8 @@ static const struct inode_operations ovl_file_inode_operations = { .get_acl = ovl_get_acl, .update_time = ovl_update_time, .fiemap = ovl_fiemap, + .fileattr_get = ovl_fileattr_get, + .fileattr_set = ovl_fileattr_set, }; static const struct inode_operations ovl_symlink_inode_operations = { diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 95cff83786a5..a1c1b5ae59e9 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -521,6 +521,9 @@ int __init ovl_aio_request_cache_init(void); void ovl_aio_request_cache_destroy(void); long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg); long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg); +int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); +int ovl_fileattr_set(struct user_namespace *mnt_userns, + struct dentry *dentry, struct fileattr *fa); /* copy_up.c */ int ovl_copy_up(struct dentry *dentry);