From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932148AbdKFJrT (ORCPT ); Mon, 6 Nov 2017 04:47:19 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:58198 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752188AbdKFJrQ (ORCPT ); Mon, 6 Nov 2017 04:47:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Seth Forshee , "Eric W. Biederman" , Sasha Levin Subject: [PATCH 4.9 55/67] vfs: open() with O_CREAT should not create inodes with unknown ids Date: Mon, 6 Nov 2017 10:44:18 +0100 Message-Id: <20171106091307.592990628@linuxfoundation.org> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171106091305.401025609@linuxfoundation.org> References: <20171106091305.401025609@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Seth Forshee [ Upstream commit 1328c727004d432bbdfba0ffa02a166df04c7305 ] may_create() rejects creation of inodes with ids which lack a mapping into s_user_ns. However for O_CREAT may_o_create() is is used instead. Add a similar check there. Fixes: 036d523641c6 ("vfs: Don't create inodes with a uid or gid unknown to the vfs") Signed-off-by: Seth Forshee Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/namei.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/namei.c +++ b/fs/namei.c @@ -2971,10 +2971,16 @@ static inline int open_to_namei_flags(in static int may_o_create(const struct path *dir, struct dentry *dentry, umode_t mode) { + struct user_namespace *s_user_ns; int error = security_path_mknod(dir, dentry, mode, 0); if (error) return error; + s_user_ns = dir->dentry->d_sb->s_user_ns; + if (!kuid_has_mapping(s_user_ns, current_fsuid()) || + !kgid_has_mapping(s_user_ns, current_fsgid())) + return -EOVERFLOW; + error = inode_permission(dir->dentry->d_inode, MAY_WRITE | MAY_EXEC); if (error) return error;