Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933611Ab2FELFS (ORCPT ); Tue, 5 Jun 2012 07:05:18 -0400 Received: from s15943758.onlinehome-server.info ([217.160.130.188]:35535 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761853Ab2FELFR (ORCPT ); Tue, 5 Jun 2012 07:05:17 -0400 Date: Tue, 5 Jun 2012 13:05:41 +0200 From: Borislav Petkov To: Christopher Yeoh Cc: Borislav Petkov , Andrew Morton , Linus Torvalds , LKML , Randy Dunlap Subject: [PATCH] CMA: Do no enable it by default Message-ID: <20120605110541.GC13495@aftab.osrc.amd.com> References: <20120531153512.GK14515@aftab.osrc.amd.com> <20120531154224.GL14515@aftab.osrc.amd.com> <20120601110647.2c446aa7@rockpopper> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120601110647.2c446aa7@rockpopper> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1773 Lines: 58 From: Borislav Petkov Date: Tue, 5 Jun 2012 12:52:01 +0200 Subject: [PATCH] CMA: Do no enable it by default From: Borislav Petkov Date: Tue, 5 Jun 2012 12:52:01 +0200 Subject: [PATCH] CMA: Do no enable it by default CROSS_MEMORY_ATTACH is a MPI feature which shouldn't be enabled by default on every linux system simply because the majority of users do not need it. Besides, in the config option it says "... which allow a process with the correct privileges to directly read from or write to to another process's address space.", which, if the reading process has somehow gained privileges (as that never happens) is your security issue right there. So disable it - people who really need that normally know what they're doing and also know how to enable it. Signed-off-by: Borislav Petkov --- mm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/Kconfig b/mm/Kconfig index 82fed4eb2b6f..3b6347cf4c06 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -352,7 +352,7 @@ endchoice config CROSS_MEMORY_ATTACH bool "Cross Memory Support" depends on MMU - default y + default n help Enabling this option adds the system calls process_vm_readv and process_vm_writev which allow a process with the correct privileges -- 1.7.11.rc1 -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach GM: Alberto Bozzo Reg: Dornach, Landkreis Muenchen HRB Nr. 43632 WEEE Registernr: 129 19551 -- 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/