From patchwork Sat Mar 18 10:15:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amir Goldstein X-Patchwork-Id: 13179738 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 E9909C77B61 for ; Sat, 18 Mar 2023 10:16:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229848AbjCRKQL (ORCPT ); Sat, 18 Mar 2023 06:16:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229959AbjCRKP6 (ORCPT ); Sat, 18 Mar 2023 06:15:58 -0400 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [IPv6:2a00:1450:4864:20::332]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DB96279A5; Sat, 18 Mar 2023 03:15:54 -0700 (PDT) Received: by mail-wm1-x332.google.com with SMTP id fm20-20020a05600c0c1400b003ead37e6588so6405116wmb.5; Sat, 18 Mar 2023 03:15:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679134554; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=hNVncBi+eLx3DXaqCOJRdjKPPS5ZKYBqno7LFhDYHyo=; b=JH9SEF/ey2pweaLNV7mCepNRPDqcG38XZ6lsqEgz6GiLnpJ+ZyPdCh9NjDLp3+kVO7 UIGir8NsTMaYk6XYDlhCahKfunhurLSKM1clpIgWA/E7UMYw8uIXMhN2Az2jV8ZZqnFq uFv3pevOFm15bJnAcdDfyn3PrIm4+9NBzXLAJmn+uozBRdJcvr2EQlIMQtWRoQGYi80H JSl/72Ab858npJxZEH3MPQQi7ZX8KirB0dvHwF35n26/Iro1/ygK0e4IFS/0okjKABOO zj5Kd1YizHV4n82tqmbTFRdd8kT5dudSkZAwDDA8ZfRLJRs0x+lvSzvD9FpSQ7SGkZ6o C5Qg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679134554; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=hNVncBi+eLx3DXaqCOJRdjKPPS5ZKYBqno7LFhDYHyo=; b=5EM9J4XulQA4SJMeAB+mmOzNHCZb0uInEpz28aABRvELHA4Z4uuJYMvQEOfvV04hbs gQpaPRGXSLyQaC9wNEhS6JHgjXbd7tWFsbucxZ7PwJse0HX5T9vYcctE9x+6Ivqt+TFN JWEbq0LjOag1Q0nywu4QpzY2rBMDGy8zfX3nvzW3+a2AFjgOMh6TdvIhAzTiC6R3Csd7 yyZy2l/TTD93rQYA7sdBGo2yrB4es9me9zmMBv8o94hpyY+33WTEmQ4xQ5c9OKk+WNh+ pLdYoAnzHoCBXKAVpi8dat7/iNUTKL05zOS3s000Y6dEGtE9c90s/8Jg2XZoMaSYWnuU q+EQ== X-Gm-Message-State: AO0yUKWzq+DgFxOUXjbwCYAeFFP0rQ+6wyWpGBB55APjAbAH+zHBdb4V wLQWJIieVDa0eDYZ5D3/W1AZo74YObA= X-Google-Smtp-Source: AK7set9ZwL7TEXVhKEgYtnfgytaWXHs6ZSpYij5gPF80VJTPA0CYOMAlwYJvX7rM0vcDhNFrh9BI0g== X-Received: by 2002:a05:600c:4f8e:b0:3e2:662:ade6 with SMTP id n14-20020a05600c4f8e00b003e20662ade6mr26346649wmq.26.1679134553874; Sat, 18 Mar 2023 03:15:53 -0700 (PDT) Received: from amir-ThinkPad-T480.lan ([5.29.249.86]) by smtp.gmail.com with ESMTPSA id v26-20020a05600c215a00b003eafc47eb09sm4333965wml.43.2023.03.18.03.15.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 18 Mar 2023 03:15:53 -0700 (PDT) From: Amir Goldstein To: Greg Kroah-Hartman Cc: Sasha Levin , "Darrick J . Wong" , Leah Rumancik , Chandan Babu R , Christian Brauner , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 5.10 11/15] fs: move should_remove_suid() Date: Sat, 18 Mar 2023 12:15:25 +0200 Message-Id: <20230318101529.1361673-12-amir73il@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230318101529.1361673-1-amir73il@gmail.com> References: <20230318101529.1361673-1-amir73il@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org 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 --- fs/attr.c | 29 +++++++++++++++++++++++++++++ fs/inode.c | 29 ----------------------------- 2 files changed, 29 insertions(+), 29 deletions(-) diff --git a/fs/attr.c b/fs/attr.c index 300ba5153868..666489157978 100644 --- 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) && diff --git a/fs/inode.c b/fs/inode.c index 63f86aeda7fd..f52dd6feea98 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1854,35 +1854,6 @@ void touch_atime(const struct path *path) } 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.