From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755215AbaKEPn1 (ORCPT ); Wed, 5 Nov 2014 10:43:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59535 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753644AbaKEPnY (ORCPT ); Wed, 5 Nov 2014 10:43:24 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 6/7] SELinux: The copy-up operation must have read permission on the lower file From: David Howells To: linux-unionfs@vger.kernel.org, selinux@tycho.nsa.gov Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 05 Nov 2014 15:43:19 +0000 Message-ID: <20141105154318.2555.7052.stgit@warthog.procyon.org.uk> In-Reply-To: <20141105154217.2555.578.stgit@warthog.procyon.org.uk> References: <20141105154217.2555.578.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The copy-up operation must have read permission on the lower file for the task that caused the copy-up. This helps prevent overlayfs from being used to access something it shouldn't. Signed-off-by: David Howells --- security/selinux/hooks.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index f43f07fdc028..57f9c641779f 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3144,7 +3144,8 @@ static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) static int selinux_inode_copy_up(struct dentry *src, struct dentry *dst) { - return 0; + const struct cred *cred = current_cred(); + return dentry_has_perm(cred, src, FILE__OPEN | FILE__READ); } static int selinux_inode_copy_up_xattr(struct dentry *src, struct dentry *dst,