From: Vasiliy Kulikov <segoon@openwall.com>
To: kernel-hardening@lists.openwall.com,
Christoph Lameter <cl@linux-foundation.org>,
Pekka Enberg <penberg@kernel.org>, Matt Mackall <mpm@selenic.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, Kees Cook <kees@ubuntu.com>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Valdis.Kletnieks@vt.edu,
Linus Torvalds <torvalds@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
Alan Cox <alan@linux.intel.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] mm: restrict access to /proc/meminfo
Date: Tue, 27 Sep 2011 23:38:10 +0400 [thread overview]
Message-ID: <20110927193810.GA5416@albatros> (raw)
In-Reply-To: <20110927175642.GA3432@albatros>
On Tue, Sep 27, 2011 at 21:56 +0400, Vasiliy Kulikov wrote:
> /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
Just to make it clear: since this patch breaks "free", I don't propose
it anymore.
> Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
> CC: Kees Cook <kees@ubuntu.com>
> CC: Dave Hansen <dave@linux.vnet.ibm.com>
> CC: Christoph Lameter <cl@gentwo.org>
> CC: Pekka Enberg <penberg@cs.helsinki.fi>
> CC: Valdis.Kletnieks@vt.edu
> CC: Linus Torvalds <torvalds@linux-foundation.org>
> CC: David Rientjes <rientjes@google.com>
> CC: Alan Cox <alan@linux.intel.com>
> ---
> 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);
--
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments
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next prev parent reply other threads:[~2011-09-27 19:39 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-27 17:54 [PATCH 1/2] mm: restrict access to slab files under procfs and sysfs Vasiliy Kulikov
2011-09-27 17:56 ` [PATCH 2/2] mm: restrict access to /proc/meminfo Vasiliy Kulikov
2011-09-27 18:27 ` David Rientjes
2011-09-27 19:14 ` Vasiliy Kulikov
2011-09-27 19:38 ` Vasiliy Kulikov [this message]
2011-09-27 20:03 ` Christoph Lameter
2011-09-27 20:33 ` David Rientjes
2011-09-27 20:47 ` Christoph Lameter
2011-09-28 20:31 ` Dave Hansen
2011-09-28 20:52 ` Alan Cox
2011-09-29 0:43 ` Valdis.Kletnieks
2011-09-29 14:11 ` Christoph Lameter
2011-09-29 16:18 ` Vasiliy Kulikov
2011-09-29 16:30 ` Dave Hansen
2011-09-29 16:43 ` [kernel-hardening] " Vasiliy Kulikov
2011-09-29 16:57 ` Valdis.Kletnieks
2011-09-29 17:25 ` [kernel-hardening] " Vasiliy Kulikov
2011-09-29 17:28 ` Vasiliy Kulikov
2011-09-28 21:46 ` Andrew Morton
2011-09-30 19:53 ` Vasiliy Kulikov
2011-09-30 20:03 ` Andrew Morton
2011-09-30 20:12 ` Vasiliy Kulikov
2011-09-30 20:15 ` Dave Hansen
2011-09-27 18:08 ` [PATCH 1/2] mm: restrict access to slab files under procfs and sysfs Christoph Lameter
2011-09-27 19:16 ` Vasiliy Kulikov
2011-09-27 19:35 ` Christoph Lameter
2011-09-27 18:21 ` David Rientjes
2011-09-27 20:00 ` Pekka Enberg
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