From patchwork Tue Feb 11 16:57:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 11376011 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 2DAFF1580 for ; Tue, 11 Feb 2020 17:01:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0CAF52086A for ; Tue, 11 Feb 2020 17:01:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730265AbgBKQ7g (ORCPT ); Tue, 11 Feb 2020 11:59:36 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:53400 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729541AbgBKQ7f (ORCPT ); Tue, 11 Feb 2020 11:59:35 -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 1j1YsU-00014T-MF; Tue, 11 Feb 2020 16:59:14 +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 09/24] capability: privileged_wrt_inode_uidgid(): handle fsid mappings Date: Tue, 11 Feb 2020 17:57:38 +0100 Message-Id: <20200211165753.356508-10-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: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Switch privileged_wrt_inode_uidgid() 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. Filesystems that share a superblock in all user namespaces they are mounted in will retain their old semantics even with the introduction of fsidmappings. Signed-off-by: Christian Brauner --- kernel/capability.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/kernel/capability.c b/kernel/capability.c index 1444f3954d75..de7edd5c9900 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -19,6 +19,8 @@ #include #include #include +#include +#include /* * Leveraged for setting/resetting capabilities @@ -484,10 +486,15 @@ EXPORT_SYMBOL(file_ns_capable); * * Return true if the inode uid and gid are within the namespace. */ -bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct inode *inode) +bool privileged_wrt_inode_uidgid(struct user_namespace *ns, + const struct inode *inode) { - return kuid_has_mapping(ns, inode->i_uid) && - kgid_has_mapping(ns, inode->i_gid); + if (is_userns_visible(inode->i_sb->s_iflags)) + return kuid_has_mapping(ns, inode->i_uid) && + kgid_has_mapping(ns, inode->i_gid); + + return kfsuid_has_mapping(ns, inode->i_uid) && + kfsgid_has_mapping(ns, inode->i_gid); } /**