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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0461C43217 for ; Fri, 20 May 2022 18:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352917AbiETShl (ORCPT ); Fri, 20 May 2022 14:37:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352925AbiETShg (ORCPT ); Fri, 20 May 2022 14:37:36 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54139195935 for ; Fri, 20 May 2022 11:37:36 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24KHT1pA016506 for ; Fri, 20 May 2022 11:37:35 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=LjQjeu05KJ6rwhAZwVJii+/tlMhhh5HkUUbhHoJms8c=; b=gC1n0WZzBxoCH+wECZ6OHpXO2phJjsKw0caLbf5hcbDm/QvQFGWdItF+soh3rCPMVpw3 NV9utU1xIasPiv5kK8jKdtsEvOru5f4B1d2whSGYC8uACCB+Uns/faMnYgy6i33432xR D8nCGT0u8IIAyAPo6cVy1QnbDrDmavascTE= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3g5pj51ugh-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 20 May 2022 11:37:35 -0700 Received: from twshared8307.18.frc3.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Fri, 20 May 2022 11:37:34 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 8E9BDF5E5B31; Fri, 20 May 2022 11:37:16 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , , Subject: [RFC PATCH v4 09/17] fs: Split off remove_needs_file_privs() __remove_file_privs() Date: Fri, 20 May 2022 11:36:38 -0700 Message-ID: <20220520183646.2002023-10-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220520183646.2002023-1-shr@fb.com> References: <20220520183646.2002023-1-shr@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: mUpnMi9iHdEe3QD163SGp75JxiY30cpc X-Proofpoint-ORIG-GUID: mUpnMi9iHdEe3QD163SGp75JxiY30cpc X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-20_06,2022-05-20_02,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org This splits off the function remove_needs_file_privs() from the function __remove_file_privs() from the function file_remove_privs(). No intended functional changes in this patch. Signed-off-by: Stefan Roesch --- fs/inode.c | 75 +++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 55 insertions(+), 20 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index 9d9b422504d1..1bb8b7db836f 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2010,17 +2010,8 @@ static int __remove_privs(struct user_namespace *m= nt_userns, return notify_change(mnt_userns, dentry, &newattrs, NULL); } =20 -/* - * Remove special file priviledges (suid, capabilities) when file is wri= tten - * to or truncated. - */ -int file_remove_privs(struct file *file) +static int file_needs_remove_privs(struct inode *inode, struct dentry *d= entry) { - struct dentry *dentry =3D file_dentry(file); - struct inode *inode =3D file_inode(file); - int kill; - int error =3D 0; - /* * Fast path for nothing security related. * As well for non-regular files, e.g. blkdev inodes. @@ -2030,16 +2021,42 @@ int file_remove_privs(struct file *file) if (IS_NOSEC(inode) || !S_ISREG(inode->i_mode)) return 0; =20 - kill =3D dentry_needs_remove_privs(dentry); - if (kill < 0) - return kill; - if (kill) - error =3D __remove_privs(file_mnt_user_ns(file), dentry, kill); + return dentry_needs_remove_privs(dentry); +} + +static int __file_remove_privs(struct file *file, struct inode *inode, + struct dentry *dentry, int kill) +{ + int error =3D 0; + + error =3D __remove_privs(file_mnt_user_ns(file), dentry, kill); if (!error) inode_has_no_xattr(inode); =20 return error; } + +/** + * file_remove_privs - remove special file privileges (suid, capabilitie= s) + * @file: file to remove privileges from + * + * When file is modified by a write or truncation ensure that special + * file privileges are removed. + * + * Return: 0 on success, negative errno on failure. + */ +int file_remove_privs(struct file *file) +{ + struct dentry *dentry =3D file_dentry(file); + struct inode *inode =3D file_inode(file); + int kill; + + kill =3D file_needs_remove_privs(inode, dentry); + if (kill <=3D 0) + return kill; + + return __file_remove_privs(file, inode, dentry, kill); +} EXPORT_SYMBOL(file_remove_privs); =20 /** @@ -2090,18 +2107,36 @@ int file_update_time(struct file *file) } EXPORT_SYMBOL(file_update_time); =20 -/* Caller must hold the file's inode lock */ +/** + * file_modified - handle mandated vfs changes when modifying a file + * @file: file that was modified + * + * When file has been modified ensure that special + * file privileges are removed and time settings are updated. + * + * Context: Caller must hold the file's inode lock. + * + * Return: 0 on success, negative errno on failure. + */ int file_modified(struct file *file) { - int err; + int ret; + struct dentry *dentry =3D file_dentry(file); + struct inode *inode =3D file_inode(file); =20 /* * Clear the security bits if the process is not being run by root. * This keeps people from modifying setuid and setgid binaries. */ - err =3D file_remove_privs(file); - if (err) - return err; + ret =3D file_needs_remove_privs(inode, dentry); + if (ret < 0) + return ret; + + if (ret > 0) { + ret =3D __file_remove_privs(file, inode, dentry, ret); + if (ret) + return ret; + } =20 if (unlikely(file->f_mode & FMODE_NOCMTIME)) return 0; --=20 2.30.2