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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,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 25895C468BC for ; Mon, 10 Jun 2019 04:18:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F32AF20861 for ; Mon, 10 Jun 2019 04:18:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726310AbfFJESc (ORCPT ); Mon, 10 Jun 2019 00:18:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56991 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726070AbfFJESc (ORCPT ); Mon, 10 Jun 2019 00:18:32 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3221137E80; Mon, 10 Jun 2019 04:18:31 +0000 (UTC) Received: from localhost (ovpn-8-23.pek2.redhat.com [10.72.8.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id B8947600CD; Mon, 10 Jun 2019 04:18:24 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , David Gibson , "Darrick J. Wong" , linux-xfs@vger.kernel.org, Alexander Viro , Christoph Hellwig Subject: [PATCH V2 0/2] block: fix page leak by merging to same page Date: Mon, 10 Jun 2019 12:18:17 +0800 Message-Id: <20190610041819.11575-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Mon, 10 Jun 2019 04:18:31 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi, 'pages' retrived by __bio_iov_iter_get_pages() may point to same page, and finally they can be merged to the same page in bio_add_page(), then page leak can be caused because bio_release_pages() only drops the page ref once. Fixes this issue by dropping the extra page ref. V2: - V1 breaks multi-page merge, and fix it and only put the page ref if the added page is really the 'same page' Ming Lei (2): block: introduce 'enum bvec_merge_flags' for __bio_try_merge_page block: fix page leak in case of merging to same page block/bio.c | 32 ++++++++++++++++++++++---------- fs/iomap.c | 3 ++- fs/xfs/xfs_aops.c | 3 ++- include/linux/bio.h | 9 ++++++++- 4 files changed, 34 insertions(+), 13 deletions(-) Cc: David Gibson Cc: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org Cc: Alexander Viro Cc: Christoph Hellwig -- 2.20.1