From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932680Ab1DYUhY (ORCPT ); Mon, 25 Apr 2011 16:37:24 -0400 Received: from 1wt.eu ([62.212.114.60]:34500 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932377Ab1DYUZL (ORCPT ); Mon, 25 Apr 2011 16:25:11 -0400 Message-Id: <20110425200237.642780335@pcw.home.local> User-Agent: quilt/0.48-1 Date: Mon, 25 Apr 2011 22:04:19 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org Cc: Kees Cook , Alexey Dobriyan , David Howells , Eugene Teo , Martin Schwidefsky , Brad Spengler , Andrew Morton , Linus Torvalds , Greg Kroah-Hartman Subject: [PATCH 107/173] proc: protect mm start_code/end_code in /proc/pid/stat In-Reply-To: <46075c3a3ef08be6d70339617d6afc98@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27.59-stable review patch. If anyone has any objections, please let us know. ------------------ From: Kees Cook commit 5883f57ca0008ffc93e09cbb9847a1928e50c6f3 upstream. While mm->start_stack was protected from cross-uid viewing (commit f83ce3e6b02d5 ("proc: avoid information leaks to non-privileged processes")), the start_code and end_code values were not. This would allow the text location of a PIE binary to leak, defeating ASLR. Note that the value "1" is used instead of "0" for a protected value since "ps", "killall", and likely other readers of /proc/pid/stat, take start_code of "0" to mean a kernel thread and will misbehave. Thanks to Brad Spengler for pointing this out. Addresses CVE-2011-0726 Signed-off-by: Kees Cook Cc: Alexey Dobriyan Cc: David Howells Cc: Eugene Teo Cc: Martin Schwidefsky Cc: Brad Spengler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/proc/array.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -473,8 +473,8 @@ static int do_task_stat(struct seq_file vsize, mm ? get_mm_rss(mm) : 0, rsslim, - mm ? mm->start_code : 0, - mm ? mm->end_code : 0, + mm ? (permitted ? mm->start_code : 1) : 0, + mm ? (permitted ? mm->end_code : 1) : 0, (permitted && mm) ? mm->start_stack : 0, esp, eip,