From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754860AbXEUBdx (ORCPT ); Sun, 20 May 2007 21:33:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754649AbXEUBdU (ORCPT ); Sun, 20 May 2007 21:33:20 -0400 Received: from mail.suse.de ([195.135.220.2]:56600 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754139AbXEUBdQ (ORCPT ); Sun, 20 May 2007 21:33:16 -0400 From: NeilBrown To: Andrew Morton Date: Mon, 21 May 2007 11:33:03 +1000 Message-Id: <1070521013303.6655@suse.de> X-face: [Gw_3E*Gng}4rRrKRYotwlE?.2|**#s9D Cc: Neil Brown Cc: stable@kernel.org Subject: [PATCH 001 of 7] md: Avoid overflow in raid0 calculation with large components. References: <20070521111837.20906.patches@notabene> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org If a raid0 has a component device larger than 4TB, and is accessed on a 32bit machines, then as 'chunk' is unsigned lock, chunk << chunksize_bits can overflow (this can be as high as the size of the device in KB). chunk itself will not overflow (without triggering a BUG). So change 'chunk' to be 'sector_t, and get rid of the 'BUG' as it becomes impossible to hit. Cc: "Jeff Zheng" Signed-off-by: Neil Brown Cc: stable@kernel.org ### Diffstat output ./drivers/md/raid0.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff .prev/drivers/md/raid0.c ./drivers/md/raid0.c --- .prev/drivers/md/raid0.c 2007-05-18 11:48:57.000000000 +1000 +++ ./drivers/md/raid0.c 2007-05-18 11:48:57.000000000 +1000 @@ -415,7 +415,7 @@ static int raid0_make_request (request_q raid0_conf_t *conf = mddev_to_conf(mddev); struct strip_zone *zone; mdk_rdev_t *tmp_dev; - unsigned long chunk; + sector_t chunk; sector_t block, rsect; const int rw = bio_data_dir(bio); @@ -470,7 +470,6 @@ static int raid0_make_request (request_q sector_div(x, zone->nb_dev); chunk = x; - BUG_ON(x != (sector_t)chunk); x = block >> chunksize_bits; tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];