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 85860C7618A for ; Mon, 20 Mar 2023 15:17:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232627AbjCTPRm (ORCPT ); Mon, 20 Mar 2023 11:17:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232520AbjCTPRV (ORCPT ); Mon, 20 Mar 2023 11:17:21 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2AED2BF2B for ; Mon, 20 Mar 2023 08:12:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 61FCEB80ED7 for ; Mon, 20 Mar 2023 15:12:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5B02C433D2; Mon, 20 Mar 2023 15:12:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1679325125; bh=36s+yBPCwCNmP3oUrD79pMYSYcEAImGt9TmYyN1OKkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N92ebbqb2FUI/5pp2Cbyg/rwUVg0oduVyb5aBtrcYYQ90eKpx+2UD7105LtHJ11/Y 5828Nsj8DQm+t2ex51YI8moa+mZqgSuDcLWPvQ5sUfCF/bp9vXn39ukk2s4FJpA45p Vpkt0OLFH5/CfsQ8N23nQQoBBJwpv+m5PUK3yPDc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Amir Goldstein , "Christian Brauner (Microsoft)" Subject: [PATCH 5.10 93/99] fs: move should_remove_suid() Date: Mon, 20 Mar 2023 15:55:11 +0100 Message-Id: <20230320145447.317102085@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230320145443.333824603@linuxfoundation.org> References: <20230320145443.333824603@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Amir Goldstein commit e243e3f94c804ecca9a8241b5babe28f35258ef4 upstream. Move the helper from inode.c to attr.c. This keeps the the core of the set{g,u}id stripping logic in one place when we add follow-up changes. It is the better place anyway, since should_remove_suid() returns ATTR_KILL_S{G,U}ID flags. Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Amir Goldstein Signed-off-by: Greg Kroah-Hartman --- fs/attr.c | 29 +++++++++++++++++++++++++++++ fs/inode.c | 29 ----------------------------- 2 files changed, 29 insertions(+), 29 deletions(-) --- a/fs/attr.c +++ b/fs/attr.c @@ -20,6 +20,35 @@ #include "internal.h" +/* + * The logic we want is + * + * if suid or (sgid and xgrp) + * remove privs + */ +int should_remove_suid(struct dentry *dentry) +{ + umode_t mode = d_inode(dentry)->i_mode; + int kill = 0; + + /* suid always must be killed */ + if (unlikely(mode & S_ISUID)) + kill = ATTR_KILL_SUID; + + /* + * sgid without any exec bits is just a mandatory locking mark; leave + * it alone. If some exec bits are set, it's a real sgid; kill it. + */ + if (unlikely((mode & S_ISGID) && (mode & S_IXGRP))) + kill |= ATTR_KILL_SGID; + + if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode))) + return kill; + + return 0; +} +EXPORT_SYMBOL(should_remove_suid); + static bool chown_ok(const struct inode *inode, kuid_t uid) { if (uid_eq(current_fsuid(), inode->i_uid) && --- a/fs/inode.c +++ b/fs/inode.c @@ -1855,35 +1855,6 @@ skip_update: EXPORT_SYMBOL(touch_atime); /* - * The logic we want is - * - * if suid or (sgid and xgrp) - * remove privs - */ -int should_remove_suid(struct dentry *dentry) -{ - umode_t mode = d_inode(dentry)->i_mode; - int kill = 0; - - /* suid always must be killed */ - if (unlikely(mode & S_ISUID)) - kill = ATTR_KILL_SUID; - - /* - * sgid without any exec bits is just a mandatory locking mark; leave - * it alone. If some exec bits are set, it's a real sgid; kill it. - */ - if (unlikely((mode & S_ISGID) && (mode & S_IXGRP))) - kill |= ATTR_KILL_SGID; - - if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode))) - return kill; - - return 0; -} -EXPORT_SYMBOL(should_remove_suid); - -/* * Return mask of changes for notify_change() that need to be done as a * response to write or truncate. Return 0 if nothing has to be changed. * Negative value on error (change should be denied).