From patchwork Tue Feb 18 14:33:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 11388705 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 8FC191395 for ; Tue, 18 Feb 2020 14:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 706C9208C4 for ; Tue, 18 Feb 2020 14:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727883AbgBROgu (ORCPT ); Tue, 18 Feb 2020 09:36:50 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:52969 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726620AbgBROff (ORCPT ); Tue, 18 Feb 2020 09:35:35 -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 1j43xz-0000fF-2a; Tue, 18 Feb 2020 14:35:15 +0000 From: Christian Brauner To: =?utf-8?q?St=C3=A9phane_Graber?= , "Eric W. Biederman" , Aleksa Sarai , Jann Horn Cc: smbarber@chromium.org, Seth Forshee , Alexander Viro , Alexey Dobriyan , Serge Hallyn , James Morris , Kees Cook , Jonathan Corbet , Phil Estes , 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 v3 11/25] inode: inode_owner_or_capable(): handle fsid mappings Date: Tue, 18 Feb 2020 15:33:57 +0100 Message-Id: <20200218143411.2389182-12-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200218143411.2389182-1-christian.brauner@ubuntu.com> References: <20200218143411.2389182-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Switch inode_owner_or_capable() 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 fsid mappings. Signed-off-by: Christian Brauner --- /* v2 */ unchanged /* v3 */ unchanged --- fs/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/inode.c b/fs/inode.c index 7d57068b6b7a..81d7a30b381d 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include "internal.h" @@ -2087,8 +2088,12 @@ bool inode_owner_or_capable(const struct inode *inode) return true; ns = current_user_ns(); - if (kuid_has_mapping(ns, inode->i_uid) && ns_capable(ns, CAP_FOWNER)) + if (is_userns_visible(inode->i_sb->s_iflags)) { + if (kuid_has_mapping(ns, inode->i_uid) && ns_capable(ns, CAP_FOWNER)) + return true; + } else if (kfsuid_has_mapping(ns, inode->i_uid) && ns_capable(ns, CAP_FOWNER)) { return true; + } return false; } EXPORT_SYMBOL(inode_owner_or_capable);