From patchwork Tue Feb 11 16:57:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 11375991 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 48C501580 for ; Tue, 11 Feb 2020 17:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 327472086A for ; Tue, 11 Feb 2020 17:00:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728787AbgBKRAk (ORCPT ); Tue, 11 Feb 2020 12:00:40 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:53431 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730108AbgBKQ7h (ORCPT ); Tue, 11 Feb 2020 11:59:37 -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 1j1YsT-00014T-Sl; Tue, 11 Feb 2020 16:59:13 +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 08/24] inode: inode_owner_or_capable(): handle fsid mappings Date: Tue, 11 Feb 2020 17:57:37 +0100 Message-Id: <20200211165753.356508-9-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 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 fsidmappings. Signed-off-by: Christian Brauner --- fs/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/inode.c b/fs/inode.c index 96d62d97694e..c1ed43c5054c 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include "internal.h" @@ -2083,8 +2084,12 @@ 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);