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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 158A2C433E6 for ; Mon, 20 Jul 2020 16:29:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DED39206E9 for ; Mon, 20 Jul 2020 16:29:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="psAR+Sve" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388640AbgGTQ3I (ORCPT ); Mon, 20 Jul 2020 12:29:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730439AbgGTP7X (ORCPT ); Mon, 20 Jul 2020 11:59:23 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2111C061794; Mon, 20 Jul 2020 08:59:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=6G9nY4eSC9xSGsf15DzhzTkdCjVU0H1/v7EwBq5HHsM=; b=psAR+SvePzTC3oMmD8sNc8v4sT RzluB0XH8DVjeqRoFEmJDFPO7DEskn9gYBX0j5shToxPH4zv/+cU9JX6I/6fpnRUtlO3Wt7JGOWOP WoeZ1xRQSuTBHIP/xU97IIPAnANsi50x+iW6CoOZKEopsLEPYlgJ1AeYBvVIll0lN5CgwDFs+oI26 sAcp2xMdEJfa01HUayr6Dr83KhEqWRk2AGsdOg1V8rrhgqikvyigT/pQiyDnlzFojdR5Q9zeNUr0G vYmJUN8n9Cx9J5KyQKSvPHDoIjZ+Y+iQeGc1M9ed++birhcJF47R7ozBtEiZUvbMTU9IEtShZr5xv tyyQd1gg==; Received: from [2001:4bb8:105:4a81:db56:edb1:dbf2:5cc3] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxYCD-0007oU-73; Mon, 20 Jul 2020 15:59:17 +0000 From: Christoph Hellwig To: Al Viro , Linus Torvalds Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org Subject: [PATCH 09/24] fs: add a kern_chown helper Date: Mon, 20 Jul 2020 17:58:47 +0200 Message-Id: <20200720155902.181712-10-hch@lst.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720155902.181712-1-hch@lst.de> References: <20200720155902.181712-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a simple helper to chown with a kernel space name and use it in the early init code instead of relying on the implicit set_fs(KERNEL_DS) there. Remove ksys_chown after switching all users to call do_fchownat directly. Signed-off-by: Christoph Hellwig --- fs/internal.h | 2 -- fs/open.c | 31 +++++++++++++++++++++---------- include/linux/fs.h | 1 + include/linux/syscalls.h | 15 +-------------- init/initramfs.c | 6 +++--- kernel/uid16.c | 6 ++++-- 6 files changed, 30 insertions(+), 31 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index 9b863a7bd70892..ad62729e7ae587 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -127,8 +127,6 @@ extern int build_open_flags(const struct open_how *how, struct open_flags *op); long do_sys_ftruncate(unsigned int fd, loff_t length, int small); int do_fchmodat(int dfd, const char __user *filename, umode_t mode); -int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, - int flag); extern int vfs_open(const struct path *, struct file *); diff --git a/fs/open.c b/fs/open.c index 2a9457a16b2be2..7d7456070503f2 100644 --- a/fs/open.c +++ b/fs/open.c @@ -714,23 +714,23 @@ static int chown_common(const struct path *path, uid_t user, gid_t group) return error; } -int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, +int do_fchownat(int dfd, struct filename *name, uid_t user, gid_t group, int flag) { struct path path; - int error = -EINVAL; - int lookup_flags; + int lookup_flags, error; + error = -EINVAL; if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) - goto out; + goto out_putname; lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; if (flag & AT_EMPTY_PATH) lookup_flags |= LOOKUP_EMPTY; retry: - error = user_path_at(dfd, filename, lookup_flags, &path); + error = filename_lookup(dfd, name, lookup_flags, &path, NULL); if (error) - goto out; + return error; error = mnt_want_write(path.mnt); if (error) goto out_release; @@ -742,24 +742,35 @@ int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, lookup_flags |= LOOKUP_REVAL; goto retry; } -out: +out_putname: + if (!IS_ERR(name)) + putname(name); return error; } +int __init kern_chown(const char *filename, uid_t user, gid_t group, int flag) +{ + return do_fchownat(AT_FDCWD, getname_kernel(filename), user, group, + flag); +} + SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, gid_t, group, int, flag) { - return do_fchownat(dfd, filename, user, group, flag); + int lookup_flags = (flag & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; + struct filename *name = getname_flags(filename, lookup_flags, NULL); + + return do_fchownat(dfd, name, user, group, flag); } SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) { - return do_fchownat(AT_FDCWD, filename, user, group, 0); + return do_fchownat(AT_FDCWD, getname(filename), user, group, 0); } SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) { - return do_fchownat(AT_FDCWD, filename, user, group, + return do_fchownat(AT_FDCWD, getname(filename), user, group, AT_SYMLINK_NOFOLLOW); } diff --git a/include/linux/fs.h b/include/linux/fs.h index 0c7672d3f1172f..75d6ef7e1de52b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3674,5 +3674,6 @@ static inline int inode_drain_writes(struct inode *inode) int kern_chdir(const char *filename); int kern_chroot(const char *filename); int __init kern_access(const char *filename, int mode); +int __init kern_chown(const char *filename, uid_t user, gid_t group, int flag); #endif /* _LINUX_FS_H */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index b387e3700c68c5..42dd2715e07688 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1326,22 +1326,9 @@ static inline int ksys_chmod(const char __user *filename, umode_t mode) return do_fchmodat(AT_FDCWD, filename, mode); } -extern int do_fchownat(int dfd, const char __user *filename, uid_t user, +extern int do_fchownat(int dfd, struct filename *name, uid_t user, gid_t group, int flag); -static inline long ksys_chown(const char __user *filename, uid_t user, - gid_t group) -{ - return do_fchownat(AT_FDCWD, filename, user, group, 0); -} - -static inline long ksys_lchown(const char __user *filename, uid_t user, - gid_t group) -{ - return do_fchownat(AT_FDCWD, filename, user, group, - AT_SYMLINK_NOFOLLOW); -} - extern long do_sys_ftruncate(unsigned int fd, loff_t length, int small); static inline long ksys_ftruncate(unsigned int fd, loff_t length) diff --git a/init/initramfs.c b/init/initramfs.c index 3823d15e5d2619..45e4ddb63caba1 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -345,14 +345,14 @@ static int __init do_name(void) } } else if (S_ISDIR(mode)) { ksys_mkdir(collected, mode); - ksys_chown(collected, uid, gid); + kern_chown(collected, uid, gid, 0); ksys_chmod(collected, mode); dir_add(collected, mtime); } else if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { if (maybe_link() == 0) { ksys_mknod(collected, mode, rdev); - ksys_chown(collected, uid, gid); + kern_chown(collected, uid, gid, 0); ksys_chmod(collected, mode); do_utime(collected, mtime); } @@ -390,7 +390,7 @@ static int __init do_symlink(void) collected[N_ALIGN(name_len) + body_len] = '\0'; clean_path(collected, 0); ksys_symlink(collected + N_ALIGN(name_len), collected); - ksys_lchown(collected, uid, gid); + kern_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW); do_utime(collected, mtime); state = SkipIt; next_state = Reset; diff --git a/kernel/uid16.c b/kernel/uid16.c index af6925d8599b9b..a332947e92d12e 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -22,12 +22,14 @@ SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group) { - return ksys_chown(filename, low2highuid(user), low2highgid(group)); + return do_fchownat(AT_FDCWD, getname(filename), low2highuid(user), + low2highgid(group), 0); } SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group) { - return ksys_lchown(filename, low2highuid(user), low2highgid(group)); + return do_fchownat(AT_FDCWD, getname(filename), low2highuid(user), + low2highgid(group), AT_SYMLINK_NOFOLLOW); } SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group) -- 2.27.0