From patchwork Mon Jun 10 09:02:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10984415 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B6DF31580 for ; Mon, 10 Jun 2019 09:02:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A525C287AD for ; Mon, 10 Jun 2019 09:02:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 970A42884E; Mon, 10 Jun 2019 09:02:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 44F9A287AD for ; Mon, 10 Jun 2019 09:02:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388406AbfFJJC3 (ORCPT ); Mon, 10 Jun 2019 05:02:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59106 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388190AbfFJJC3 (ORCPT ); Mon, 10 Jun 2019 05:02:29 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 60827C057EC6; Mon, 10 Jun 2019 09:02:24 +0000 (UTC) Received: from localhost (ovpn-8-22.pek2.redhat.com [10.72.8.22]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0F48E60C64; Mon, 10 Jun 2019 09:02:19 +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 V3 0/2] block: fix page leak by merging to same page Date: Mon, 10 Jun 2019 17:02:13 +0800 Message-Id: <20190610090215.14412-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 10 Jun 2019 09:02:29 +0000 (UTC) Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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. V3: - avoid to call __bio_try_merge_page() two times - add comment on the two new flags 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 | 22 +++++++++++++++++++++- 4 files changed, 47 insertions(+), 13 deletions(-) Cc: David Gibson Cc: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org Cc: Alexander Viro Cc: Christoph Hellwig