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=-9.8 required=3.0 tests=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 27C85C352A3 for ; Tue, 11 Feb 2020 16:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F07BC2086A for ; Tue, 11 Feb 2020 16:59:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731037AbgBKQ7t (ORCPT ); Tue, 11 Feb 2020 11:59:49 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:53492 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730986AbgBKQ7p (ORCPT ); Tue, 11 Feb 2020 11:59:45 -0500 Received: from ip5f5bf7ec.dynamic.kabel-deutschland.de ([95.91.247.236] helo=wittgenstein.fritz.box) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1j1Ysf-00014T-4B; Tue, 11 Feb 2020 16:59:25 +0000 From: Christian Brauner To: =?UTF-8?q?St=C3=A9phane=20Graber?= , "Eric W. Biederman" , Aleksa Sarai , Jann Horn Cc: smbarber@chromium.org, Alexander Viro , Alexey Dobriyan , Serge Hallyn , James Morris , Kees Cook , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, Christian Brauner Subject: [PATCH 19/24] sys:__sys_setgid(): handle fsid mappings Date: Tue, 11 Feb 2020 17:57:48 +0100 Message-Id: <20200211165753.356508-20-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200211165753.356508-1-christian.brauner@ubuntu.com> References: <20200211165753.356508-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Switch setgid() to lookup fsids in the fsid mappings. If no fsid mappings are setup the behavior is unchanged, i.e. fsids are looked up in the id mappings. Signed-off-by: Christian Brauner --- kernel/sys.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/kernel/sys.c b/kernel/sys.c index afaec8d46bc5..11f41e0a4974 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -416,24 +416,31 @@ long __sys_setgid(gid_t gid) const struct cred *old; struct cred *new; int retval; - kgid_t kgid; + kgid_t kgid, kfsgid; kgid = make_kgid(ns, gid); if (!gid_valid(kgid)) return -EINVAL; + kfsgid = make_kfsgid(ns, gid); + if (!gid_valid(kfsgid)) + return -EINVAL; + new = prepare_creds(); if (!new) return -ENOMEM; old = current_cred(); retval = -EPERM; - if (ns_capable(old->user_ns, CAP_SETGID)) - new->gid = new->egid = new->sgid = new->fsgid = kgid; - else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) - new->egid = new->fsgid = kgid; - else + if (ns_capable(old->user_ns, CAP_SETGID)) { + new->gid = new->egid = new->sgid = kgid; + new->fsgid = kfsgid; + } else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) { + new->egid = kgid; + new->fsgid = kfsgid; + } else { goto error; + } return commit_creds(new); -- 2.25.0