From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752141Ab3FEGnG (ORCPT ); Wed, 5 Jun 2013 02:43:06 -0400 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:47449 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751474Ab3FEGnD (ORCPT ); Wed, 5 Jun 2013 02:43:03 -0400 X-AuditID: 9c930179-b7c1dae000003992-b5-51aeddf52d22 Date: Wed, 5 Jun 2013 15:43:01 +0900 From: Minchan Kim To: Jiang Liu Cc: Greg Kroah-Hartman , Nitin Gupta , Jerome Marchand , Yijing Wang , Jiang Liu , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 06/10] zram: avoid access beyond the zram device Message-ID: <20130605064301.GF8732@blaptop> References: <1370361968-8764-1-git-send-email-jiang.liu@huawei.com> <1370361968-8764-6-git-send-email-jiang.liu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1370361968-8764-6-git-send-email-jiang.liu@huawei.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 05, 2013 at 12:06:04AM +0800, Jiang Liu wrote: > Function valid_io_request() should verify the entire request doesn't > exceed the zram device, otherwise it will cause invalid memory access. Right but you need to explain what invalid memory access is and what's the result from that to user. > > Signed-off-by: Jiang Liu > Cc: stable@vger.kernel.org > --- > drivers/staging/zram/zram_drv.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c > index 6a54bb9..1c3974f 100644 > --- a/drivers/staging/zram/zram_drv.c > +++ b/drivers/staging/zram/zram_drv.c > @@ -428,6 +428,10 @@ static inline int valid_io_request(struct zram *zram, struct bio *bio) > return 0; > } > > + if (unlikely((bio->bi_sector << SECTOR_SHIFT) + bio->bi_size >= > + zram->disksize)) > + return 0; > + > /* I/O request is valid */ > return 1; > } > -- > 1.8.1.2 > > -- > 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/ -- Kind regards, Minchan Kim