Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933423Ab1CZAKk (ORCPT ); Fri, 25 Mar 2011 20:10:40 -0400 Received: from kroah.org ([198.145.64.141]:35890 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932709Ab1CZAGd (ORCPT ); Fri, 25 Mar 2011 20:06:33 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Mar 25 17:04:58 2011 Message-Id: <20110326000457.907954931@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Fri, 25 Mar 2011 17:03:52 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Kees Cook , Alexey Dobriyan , David Howells , Eugene Teo , Martin Schwidefsky , Brad Spengler Subject: [20/35] proc: protect mm start_code/end_code in /proc/pid/stat In-Reply-To: <20110326000509.GA29736@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1868 Lines: 54 2.6.33-longterm 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 @@ -488,8 +488,8 @@ 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, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/