From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC9DEC282DA for ; Wed, 17 Apr 2019 11:52:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82C4A20835 for ; Wed, 17 Apr 2019 11:52:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731996AbfDQLwx (ORCPT ); Wed, 17 Apr 2019 07:52:53 -0400 Received: from mx2.suse.de ([195.135.220.15]:43262 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729898AbfDQLwx (ORCPT ); Wed, 17 Apr 2019 07:52:53 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E96F2AFFB; Wed, 17 Apr 2019 11:52:51 +0000 (UTC) Subject: Re: [PATCH] block: make sure that bvec length can't be overflowed To: Ming Lei , Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Yi Zhang References: <20190416153847.8173-1-ming.lei@redhat.com> From: Hannes Reinecke Message-ID: Date: Wed, 17 Apr 2019 13:52:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190416153847.8173-1-ming.lei@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 4/16/19 5:38 PM, Ming Lei wrote: > bvec->bv_offset may be bigger than PAGE_SIZE sometimes, such as, > when one bio is splitted in the middle of one bvec via bio_split(), > and bi_iter.bi_bvec_done is used to build offset of the 1st bvec of > remained bio. > > So we have to make sure that every bvec's offset is less than > PAGE_SIZE from bio_for_each_segment(). > > This patch fixes this issue reported by Zhang Yi When running nvme/011. > > Cc: Christoph Hellwig > Cc: Yi Zhang > Reported-by: Yi Zhang > Fixes: 6dc4f100c175 ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec") > Signed-off-by: Ming Lei > --- > include/linux/bvec.h | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/include/linux/bvec.h b/include/linux/bvec.h > index 3bc91879e1e2..f179b370066f 100644 > --- a/include/linux/bvec.h > +++ b/include/linux/bvec.h > @@ -160,8 +160,9 @@ static inline void bvec_advance(const struct bio_vec *bvec, > bv->bv_page = nth_page(bv->bv_page, 1); > bv->bv_offset = 0; > } else { > - bv->bv_page = bvec->bv_page; > - bv->bv_offset = bvec->bv_offset; > + bv->bv_page = bvec_nth_page(bvec->bv_page, bvec->bv_offset / > + PAGE_SIZE); > + bv->bv_offset = bvec->bv_offset % PAGE_SIZE; > } > bv->bv_len = min_t(unsigned int, PAGE_SIZE - bv->bv_offset, > bvec->bv_len - iter_all->done); > Looks okay. Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg)