From patchwork Tue Feb 11 16:57:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 11375959 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 8D64417F0 for ; Tue, 11 Feb 2020 17:00:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77668215A4 for ; Tue, 11 Feb 2020 17:00:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731062AbgBKRAE (ORCPT ); Tue, 11 Feb 2020 12:00:04 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:53471 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729829AbgBKQ7l (ORCPT ); Tue, 11 Feb 2020 11:59:41 -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 1j1Ysd-00014T-Qv; Tue, 11 Feb 2020 16:59:23 +0000 From: Christian Brauner To: =?utf-8?q?St=C3=A9phane_Graber?= , "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 18/24] sys:__sys_setuid(): handle fsid mappings Date: Tue, 11 Feb 2020 17:57:47 +0100 Message-Id: <20200211165753.356508-19-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 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Switch setuid() 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 | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/kernel/sys.c b/kernel/sys.c index b89334ad0908..afaec8d46bc5 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -574,11 +574,16 @@ long __sys_setuid(uid_t uid) struct cred *new; int retval; kuid_t kuid; + kuid_t kfsuid; kuid = make_kuid(ns, uid); if (!uid_valid(kuid)) return -EINVAL; + kfsuid = make_kfsuid(ns, uid); + if (!uid_valid(kfsuid)) + return -EINVAL; + new = prepare_creds(); if (!new) return -ENOMEM; @@ -596,7 +601,8 @@ long __sys_setuid(uid_t uid) goto error; } - new->fsuid = new->euid = kuid; + new->euid = kuid; + new->fsuid = kfsuid; retval = security_task_fix_setuid(new, old, LSM_SETID_ID); if (retval < 0)