From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762322AbXHKS7r (ORCPT ); Sat, 11 Aug 2007 14:59:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762332AbXHKS6M (ORCPT ); Sat, 11 Aug 2007 14:58:12 -0400 Received: from 1wt.eu ([62.212.114.60]:1492 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762222AbXHKS6I (ORCPT ); Sat, 11 Aug 2007 14:58:08 -0400 From: Willy Tarreau Message-Id: <20070811184829.%N@1wt.eu> References: <20070811184752.%N@1wt.eu> User-Agent: quilt/0.46-1 Date: Sat, 11 Aug 2007 21:47:54 +0200 To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: "Jeff Zheng" , Neil Brown , Chris Wright , Greg Kroah-Hartman Subject: [2.6.20.16 review 02/28] md: Avoid overflow in raid0 calculation with large components. Content-Disposition: inline; filename=0002-PATCH-md-Avoid-overflow-in-raid0-calculation-with.patch 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 Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman --- drivers/md/raid0.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index dfe3214..2c404f7 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -415,7 +415,7 @@ static int raid0_make_request (request_queue_t *q, struct bio *bio) 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_queue_t *q, struct bio *bio) 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)]; -- 1.5.2.4 --