From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752686Ab1I0R5f (ORCPT ); Tue, 27 Sep 2011 13:57:35 -0400 Received: from mail-bw0-f46.google.com ([209.85.214.46]:63582 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752248Ab1I0R5e (ORCPT ); Tue, 27 Sep 2011 13:57:34 -0400 Date: Tue, 27 Sep 2011 21:56:42 +0400 From: Vasiliy Kulikov To: kernel-hardening@lists.openwall.com, Christoph Lameter , Pekka Enberg , Matt Mackall , Andrew Morton Cc: linux-mm@kvack.org, Kees Cook , Dave Hansen , Valdis.Kletnieks@vt.edu, Linus Torvalds , David Rientjes , Alan Cox , linux-kernel@vger.kernel.org Subject: [PATCH 2/2] mm: restrict access to /proc/meminfo Message-ID: <20110927175642.GA3432@albatros> References: <20110927175453.GA3393@albatros> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110927175453.GA3393@albatros> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org /proc/meminfo stores information related to memory pages usage, which may be used to monitor the number of objects in specific caches (and/or the changes of these numbers). This might reveal private information similar to /proc/slabinfo infoleaks. To remove the infoleak, just restrict meminfo to root. If it is used by unprivileged daemons, meminfo permissions can be altered the same way as slabinfo: groupadd meminfo usermod -a -G meminfo $MONITOR_USER chmod g+r /proc/meminfo chgrp meminfo /proc/meminfo Signed-off-by: Vasiliy Kulikov CC: Kees Cook CC: Dave Hansen CC: Christoph Lameter CC: Pekka Enberg CC: Valdis.Kletnieks@vt.edu CC: Linus Torvalds CC: David Rientjes CC: Alan Cox --- fs/proc/meminfo.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) -- diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index 5861741..949bdee 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -187,7 +187,7 @@ static const struct file_operations meminfo_proc_fops = { static int __init proc_meminfo_init(void) { - proc_create("meminfo", 0, NULL, &meminfo_proc_fops); + proc_create("meminfo", S_IFREG | S_IRUSR, NULL, &meminfo_proc_fops); return 0; } module_init(proc_meminfo_init);