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 EABC6C433F5 for ; Thu, 14 Apr 2022 06:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240170AbiDNG7N (ORCPT ); Thu, 14 Apr 2022 02:59:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239661AbiDNG7M (ORCPT ); Thu, 14 Apr 2022 02:59:12 -0400 Received: from mail1.bemta34.messagelabs.com (mail1.bemta34.messagelabs.com [195.245.231.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2579553B6A; Wed, 13 Apr 2022 23:56:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fujitsu.com; s=170520fj; t=1649919404; i=@fujitsu.com; bh=smQK4tppl/0P9em1n4iYPJctoNQAJ0+xEhuhlGR6/yo=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=dNssRrL8fwslrgqW+PO0yGjf9kORsjhaLDTfviMxuaZKFNz6npRlsUkRygC8ygEAH 0GvWr8VPlDf62bbfYzsqOhATAU7INj+TRMviadPB5hpdZkkRlQ/uKT2JntEQJCg0Uu 1WsO3K5QHCNx+KllaZGuD0bKB4hYDeNB3+YguNmdrnUKgeQtrwbzakLDrU4R5NAcJx h2LeN46ITYIOh1KUxE26FBoce4k2B+Aj0a5aeknNT4Irt5K3olLtHvU8vkx6Vi2FGu jNEMJB5bjsrIF3v6q0x2kAVfXjzZkd+fK3Hy6DaOID3WN+TmTZ34UoBSPS0sSqS35/ hA9etSp39u4NQ== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrBIsWRWlGSWpSXmKPExsViZ8MxSXf10fA kgyUzLSxeH/7EaPHh5iQmiy3H7jFaXH7CZ/Fz2Sp2iz17T7JY7Hpzjt3i/N/jrA4cHqcWSXhs WtXJ5nFh2Rs2j8+b5Dw2PXnLFMAaxZqZl5RfkcCa0fRermAdb8W63YuZGxjXcXcxcnEICWxhl Li3eB4rhLOASeLk5XmMEM4eRomnjdvZuhg5OdgENCWedS5gBrFFBBIkXt9azAxSxCwwh1Hi8Y nbYEXCAuYSG7cfYwGxWQRUJf51zGYHsXkFPCR+vH0AViMhoCAx5eF7Zoi4oMTJmU/A6pkFJCQ OvnjBDFGjKHGp4xsjhF0hMWtWGxOErSZx9dwm5gmM/LOQtM9C0r6AkWkVo3VSUWZ6RkluYmaO rqGBga6hoamusZGuoYWlXmKVbqJeaqlueWpxia6RXmJ5sV5qcbFecWVuck6KXl5qySZGYASkF Cvs3cF4eeVPvUOMkhxMSqK8TcDYEOJLyk+pzEgszogvKs1JLT7EKMPBoSTB+/8IUE6wKDU9tS ItMwcYjTBpCQ4eJRFeP5BW3uKCxNzizHSI1ClGRSlx3tUgfQIgiYzSPLg2WAK4xCgrJczLyMD AIMRTkFqUm1mCKv+KUZyDUUmY9wLIFJ7MvBK46a+AFjMBLf62KhRkcUkiQkqqgUn/3vOLi/O7 pZX7dq1a8ntJlvDHMnFnRYHgJ1Pl1+3uTj543P1B//28XckTPEOPFFy16OjOS/rR9+t90/WGu Q/+mDB4lqlfuaJv33Sc21D5hZpFRH2Z99qKR743TeVzXxy6vLtFs2t6UsOjv9cKW3uncUcVsb ncX3JOWM7+rIjk/SD/rcz5aWx6VldY5uj82BbnG9rlUPP5rrjnw0+beS9L3XRPvnyjZ7egL3N H3Ow9Ljw/rnAuUGWYHCrMVhfFzfq/bZKQe7b48q3vFon5z6hVv5sYl/nqVefTMqH6u8z/FZyP +zhYaRfONPWIl//YUsdQaP5ig2Zp15a9c07s2+5R3F2doiIf+Hl3eUWvEktxRqKhFnNRcSIAZ wmOD3sDAAA= X-Env-Sender: xuyang2018.jy@fujitsu.com X-Msg-Ref: server-11.tower-548.messagelabs.com!1649919403!222910!1 X-Originating-IP: [62.60.8.146] X-SYMC-ESS-Client-Auth: outbound-route-from=pass X-StarScan-Received: X-StarScan-Version: 9.85.8; banners=-,-,- X-VirusChecked: Checked Received: (qmail 22917 invoked from network); 14 Apr 2022 06:56:43 -0000 Received: from unknown (HELO n03ukasimr02.n03.fujitsu.local) (62.60.8.146) by server-11.tower-548.messagelabs.com with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 14 Apr 2022 06:56:43 -0000 Received: from n03ukasimr02.n03.fujitsu.local (localhost [127.0.0.1]) by n03ukasimr02.n03.fujitsu.local (Postfix) with ESMTP id 818E7100472; Thu, 14 Apr 2022 07:56:43 +0100 (BST) Received: from R01UKEXCASM126.r01.fujitsu.local (unknown [10.183.43.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by n03ukasimr02.n03.fujitsu.local (Postfix) with ESMTPS id 743A6100467; Thu, 14 Apr 2022 07:56:43 +0100 (BST) Received: from localhost.localdomain (10.167.220.84) by R01UKEXCASM126.r01.fujitsu.local (10.183.43.178) with Microsoft SMTP Server (TLS) id 15.0.1497.32; Thu, 14 Apr 2022 07:56:32 +0100 From: Yang Xu To: , , CC: , , , , , Yang Xu Subject: [PATCH v2 1/3] vfs: Add inode_sgid_strip() api Date: Thu, 14 Apr 2022 15:57:17 +0800 Message-ID: <1649923039-2273-1-git-send-email-xuyang2018.jy@fujitsu.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.167.220.84] X-ClientProxiedBy: G08CNEXCHPEKD07.g08.fujitsu.local (10.167.33.80) To R01UKEXCASM126.r01.fujitsu.local (10.183.43.178) X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org inode_sgid_strip() function is used to strip S_ISGID mode when creat/open/mknod file. Reviewed-by: Christian Brauner (Microsoft) Signed-off-by: Yang Xu --- fs/inode.c | 18 ++++++++++++++++++ include/linux/fs.h | 3 ++- 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/inode.c b/fs/inode.c index 9d9b422504d1..d63264998855 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2405,3 +2405,21 @@ struct timespec64 current_time(struct inode *inode) return timestamp_truncate(now, inode); } EXPORT_SYMBOL(current_time); + +void inode_sgid_strip(struct user_namespace *mnt_userns, struct inode *dir, + umode_t *mode) +{ + if (!dir || !(dir->i_mode & S_ISGID)) + return; + if ((*mode & (S_ISGID | S_IXGRP)) != (S_ISGID | S_IXGRP)) + return; + if (S_ISDIR(*mode)) + return; + if (in_group_p(i_gid_into_mnt(mnt_userns, dir))) + return; + if (capable_wrt_inode_uidgid(mnt_userns, dir, CAP_FSETID)) + return; + + *mode &= ~S_ISGID; +} +EXPORT_SYMBOL(inode_sgid_strip); diff --git a/include/linux/fs.h b/include/linux/fs.h index bbde95387a23..94d94219fe7c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1897,7 +1897,8 @@ extern long compat_ptr_ioctl(struct file *file, unsigned int cmd, void inode_init_owner(struct user_namespace *mnt_userns, struct inode *inode, const struct inode *dir, umode_t mode); extern bool may_open_dev(const struct path *path); - +void inode_sgid_strip(struct user_namespace *mnt_userns, struct inode *dir, + umode_t *mode); /* * This is the "filldir" function type, used by readdir() to let * the kernel specify what kind of dirent layout it wants to have. -- 2.27.0