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 28056C4167B for ; Tue, 26 Apr 2022 17:44:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349265AbiDZRrR (ORCPT ); Tue, 26 Apr 2022 13:47:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41708 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353595AbiDZRrP (ORCPT ); Tue, 26 Apr 2022 13:47:15 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA06A183240 for ; Tue, 26 Apr 2022 10:44:06 -0700 (PDT) Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 23QGQTVr003393 for ; Tue, 26 Apr 2022 10:44:06 -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=+WNxfbgx5KplNQxILus6+cfK8Ur0YvLuT9aWWjF0PNM=; b=PSN+MFz5/TGIG15H4ZKgPAhVr+GPLFFt16AoWbGSIqe1+0qGfSF5u2dEfcVwjXbxCxCZ HD9spi/LttKnCjC2T71fmfSrVOvKfX1WrNqWxAe5Yp23aboswFsl6ucv29PYkZmx7cTK Yfxo/KcYFPHfPcVhukTZr7hISzn9qZuSymA= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3fp6a352pe-5 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 26 Apr 2022 10:44:06 -0700 Received: from twshared13345.18.frc3.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 26 Apr 2022 10:44:02 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 9BB50E2D4861; Tue, 26 Apr 2022 10:43:40 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , Subject: [RFC PATCH v1 07/18] fs: split off need_remove_file_privs() do_remove_file_privs() Date: Tue, 26 Apr 2022 10:43:24 -0700 Message-ID: <20220426174335.4004987-8-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220426174335.4004987-1-shr@fb.com> References: <20220426174335.4004987-1-shr@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: Sgen28DxzGu0PGXxJJmoE7cmwkfuUXCX X-Proofpoint-ORIG-GUID: Sgen28DxzGu0PGXxJJmoE7cmwkfuUXCX X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-04-26_05,2022-04-26_02,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org This splits off the function need_remove_file_privs() from the function do_remove_file_privs() from the function file_remove_privs(). No intended functional changes in this patch. Signed-off-by: Stefan Roesch --- fs/inode.c | 56 +++++++++++++++++++++++++++++++--------------- include/linux/fs.h | 3 +++ 2 files changed, 41 insertions(+), 18 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index 9d9b422504d1..79c5702ef7c3 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) +int need_file_remove_privs(struct inode *inode, struct dentry *dentry) { - 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 +2021,37 @@ 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); +} + +int do_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; } + +/* + * Remove special file privileges (suid, capabilities) when file is writ= ten + * to or truncated. + */ +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 need_file_remove_privs(inode, dentry); + if (kill <=3D 0) + return kill; + + return do_file_remove_privs(file, inode, dentry, kill); +} EXPORT_SYMBOL(file_remove_privs); =20 /** @@ -2094,14 +2106,22 @@ EXPORT_SYMBOL(file_update_time); 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 need_file_remove_privs(inode, dentry); + if (ret < 0) { + return ret; + } else if (ret > 0) { + ret =3D do_file_remove_privs(file, inode, dentry, ret); + if (ret) + return ret; + } =20 if (unlikely(file->f_mode & FMODE_NOCMTIME)) return 0; diff --git a/include/linux/fs.h b/include/linux/fs.h index 3b479d02e210..c2992d12601f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2381,6 +2381,9 @@ static inline void file_accessed(struct file *file) touch_atime(&file->f_path); } =20 +extern int need_file_remove_privs(struct inode *inode, struct dentry *de= ntry); +extern int do_file_remove_privs(struct file *file, struct inode *inode, + struct dentry *dentry, int kill); extern int file_modified(struct file *file); =20 int sync_inode_metadata(struct inode *inode, int wait); --=20 2.30.2