From patchwork Tue Jul 28 16:34:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11689515 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 483861392 for ; Tue, 28 Jul 2020 16:34:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30D1820829 for ; Tue, 28 Jul 2020 16:34:57 +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="jNuHn6EW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731720AbgG1Qew (ORCPT ); Tue, 28 Jul 2020 12:34:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731709AbgG1Qeu (ORCPT ); Tue, 28 Jul 2020 12:34:50 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1753DC061794; Tue, 28 Jul 2020 09:34:50 -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=U6/jNKrxAUIjzQ18kwUZySI+bueeC5+chL9pO9InTCg=; b=jNuHn6EW67qenzbx2RviE1Lh+R w369i05ZeMR5zgBppkJJuPGHwLtd1wmqu/UUkvm3HvpuPKXqb5oVyuO/lO19VSxI5s2FH3LlpZFz4 JdK6wffIbRHJILl2fWrVKGoiS9Pf0WRJ8auweugKcgXPel1kj39QlPWSh6xY0H5gfrZHqZh0CityY tgqkd/cPG+5tuugTkOqjm4m2I5hUTZfYi8cqNT/EEuQHqzHlsn4u7zbCNZUxD4ZH7A0kIOt0Afpmn ddO/m8q9I31AjNGFsyJ/8q28gPT16W9jpUvCwsyK8DC9W4SI2XfbFtejyAtRt3CN00iBeB7zrmUUb iz+nI5cw==; Received: from [2001:4bb8:180:6102:fd04:50d8:4827:5508] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0SYu-00071A-1t; Tue, 28 Jul 2020 16:34:44 +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 14/23] init: add an init_chown helper Date: Tue, 28 Jul 2020 18:34:07 +0200 Message-Id: <20200728163416.556521-15-hch@lst.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200728163416.556521-1-hch@lst.de> References: <20200728163416.556521-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add a simple helper to chown with a kernel space file name and switch the early init code over to it. Signed-off-by: Christoph Hellwig --- fs/init.c | 18 ++++++++++++++++++ fs/internal.h | 2 +- fs/open.c | 2 +- include/linux/init_syscalls.h | 1 + init/initramfs.c | 6 +++--- 5 files changed, 24 insertions(+), 5 deletions(-) diff --git a/fs/init.c b/fs/init.c index 2c78f24814dde4..edd0244655956e 100644 --- a/fs/init.c +++ b/fs/init.c @@ -78,6 +78,24 @@ int __init init_chroot(const char *filename) return error; } +int __init init_chown(const char *filename, uid_t user, gid_t group, int flags) +{ + int lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; + struct path path; + int error; + + error = kern_path(filename, lookup_flags, &path); + if (error) + return error; + error = mnt_want_write(path.mnt); + if (!error) { + error = chown_common(&path, user, group); + mnt_drop_write(path.mnt); + } + path_put(&path); + return error; +} + int __init init_unlink(const char *pathname) { return do_unlinkat(AT_FDCWD, getname_kernel(pathname)); diff --git a/fs/internal.h b/fs/internal.h index 491d1e63809b37..e81b9e23c3ea3f 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -134,7 +134,7 @@ 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); - +int chown_common(const struct path *path, uid_t user, gid_t group); extern int vfs_open(const struct path *, struct file *); /* diff --git a/fs/open.c b/fs/open.c index f62f4752bb436d..49960a1248f14b 100644 --- a/fs/open.c +++ b/fs/open.c @@ -639,7 +639,7 @@ SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) return do_fchmodat(AT_FDCWD, filename, mode); } -static int chown_common(const struct path *path, uid_t user, gid_t group) +int chown_common(const struct path *path, uid_t user, gid_t group) { struct inode *inode = path->dentry->d_inode; struct inode *delegated_inode = NULL; diff --git a/include/linux/init_syscalls.h b/include/linux/init_syscalls.h index e07099a14b91db..0da59d76133e17 100644 --- a/include/linux/init_syscalls.h +++ b/include/linux/init_syscalls.h @@ -5,5 +5,6 @@ int __init init_mount(const char *dev_name, const char *dir_name, int __init init_umount(const char *name, int flags); int __init init_chdir(const char *filename); int __init init_chroot(const char *filename); +int __init init_chown(const char *filename, uid_t user, gid_t group, int flags); int __init init_unlink(const char *pathname); int __init init_rmdir(const char *pathname); diff --git a/init/initramfs.c b/init/initramfs.c index fb7210731d9e5d..24a8dcc6734064 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -349,14 +349,14 @@ static int __init do_name(void) } } else if (S_ISDIR(mode)) { ksys_mkdir(collected, mode); - ksys_chown(collected, uid, gid); + init_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); + init_chown(collected, uid, gid, 0); ksys_chmod(collected, mode); do_utime(collected, mtime); } @@ -394,7 +394,7 @@ 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); + init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW); do_utime(collected, mtime); state = SkipIt; next_state = Reset;