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=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 EFC44C4338F for ; Sun, 8 Aug 2021 12:58:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D04EF60EBC for ; Sun, 8 Aug 2021 12:58:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230049AbhHHM6h (ORCPT ); Sun, 8 Aug 2021 08:58:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229504AbhHHM6h (ORCPT ); Sun, 8 Aug 2021 08:58:37 -0400 Received: from mail-wr1-x433.google.com (mail-wr1-x433.google.com [IPv6:2a00:1450:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB3DFC061760 for ; Sun, 8 Aug 2021 05:58:17 -0700 (PDT) Received: by mail-wr1-x433.google.com with SMTP id h13so17601384wrp.1 for ; Sun, 08 Aug 2021 05:58:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=oVDlGo2/GL5fB+ntlbYoUjx1btQ2ylvhx4xcIT+a7JE=; b=OW5Jg23oqret+mODZTBn4D1bPm3sybVmDlOjs2gnp5sTcGD/j9RK1957DXetQIXMPf 0v337D4DslKw78ATcvv0tFVU9ASX/gC2aE1KTApARVVgO9EQPzInEKmvRSVm+H7bieab jFFWlkulsJ7hZFbj73ZME/7d1BGAYVPfLh/h54Y6lXpFoiYOI9x6aAASu/7p3a4UkZoG evnJtpgj1+SGrQRro3SVV1SxxNIeSyEde6eooDQntoeuwAtUE0J1aFUC0FFqtxw3ZldV w+OF4VM9WdgO+IxcP9wJOnIMrahF3imtAp197w4atM7TnlcbfO855gpUodMzBjiZlDYj b42Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=oVDlGo2/GL5fB+ntlbYoUjx1btQ2ylvhx4xcIT+a7JE=; b=bbYGSaGdXXcxOpVaCpFwaqhdPY2+2EgT75iNzkVcL0LgSpjcuW3lFozjexIke2ejLh Boy9EGijFdHO8XHB+PLdqLtOHYg8dabmUWMRCGbP//GA5N7IEJvvCciDggA5inulQpZM ZPz2D45C9c5A2Q1R2FrzDm3vFQnK9HCN1/vHkFyTpYuQavhR6g5alhBenHkralkP/zK/ rAkEM411GWhr4nKHcAfga20TPi/EolucgExF2VA5Q61miz98TxAkKxsCQqVwTNy5o95A FUHfuOXRjQ+5Ql2JCq7bHE1IHjRBx52Q93ZV3Ewav5rvqVBvm0Qnley8ZS05cNTrAHar FiMQ== X-Gm-Message-State: AOAM533/8pnWqXBkjseSQAJC+5D/RGrOvBn3cAmRGbqJuMq0uvsHa52r w6w5HFg3uGg7QLijsdrWKFE= X-Google-Smtp-Source: ABdhPJzxfquvsXBpIQ6dchayeIcUF3WJmoU01wO5Z6RQZK21cJFRitCJchBdX5aQu8BM7V3nNL8Kkw== X-Received: by 2002:a05:6000:7:: with SMTP id h7mr20079315wrx.298.1628427496401; Sun, 08 Aug 2021 05:58:16 -0700 (PDT) Received: from [192.168.8.197] ([85.255.236.119]) by smtp.gmail.com with ESMTPSA id i5sm15860560wrw.13.2021.08.08.05.58.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 08 Aug 2021 05:58:15 -0700 (PDT) Subject: Re: [RFC] bio: fix page leak bio_add_hw_page failure To: Jens Axboe , linux-block@vger.kernel.org Cc: Keith Busch References: <1edfa6a2ffd66d55e6345a477df5387d2c1415d0.1626653825.git.asml.silence@gmail.com> From: Pavel Begunkov Message-ID: <49550f27-2dac-7ee5-1e03-bd22b70b7ca1@gmail.com> Date: Sun, 8 Aug 2021 13:57:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <1edfa6a2ffd66d55e6345a477df5387d2c1415d0.1626653825.git.asml.silence@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 7/19/21 11:53 AM, Pavel Begunkov wrote: > __bio_iov_append_get_pages() doesn't put not appended pages on > bio_add_hw_page() failure, so potentially leaking them, fix it. Also, do > the same for __bio_iov_iter_get_pages(), even though it looks like it > can't be triggered by userspace in this case. Any comments? > > Fixes: 0512a75b98f8 ("block: Introduce REQ_OP_ZONE_APPEND") > Cc: stable@vger.kernel.org # 5.8+ > Signed-off-by: Pavel Begunkov > --- > > I haven't tested the fail path, thus RFC. Would be great if someone can > do it or take over the fix. > > block/bio.c | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) > > diff --git a/block/bio.c b/block/bio.c > index 1fab762e079b..d95e3456ba0c 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -979,6 +979,14 @@ static int bio_iov_bvec_set_append(struct bio *bio, struct iov_iter *iter) > return 0; > } > > +static void bio_put_pages(struct page **pages, size_t size, size_t off) > +{ > + size_t i, nr = DIV_ROUND_UP(size + (off & ~PAGE_MASK), PAGE_SIZE); > + > + for (i = 0; i < nr; i++) > + put_page(pages[i]); > +} > + > #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) > > /** > @@ -1023,8 +1031,10 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) > if (same_page) > put_page(page); > } else { > - if (WARN_ON_ONCE(bio_full(bio, len))) > - return -EINVAL; > + if (WARN_ON_ONCE(bio_full(bio, len))) { > + bio_put_pages(pages + i, left, offset); > + return -EINVAL; > + } > __bio_add_page(bio, page, len, offset); > } > offset = 0; > @@ -1069,6 +1079,7 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter) > len = min_t(size_t, PAGE_SIZE - offset, left); > if (bio_add_hw_page(q, bio, page, len, offset, > max_append_sectors, &same_page) != len) { > + bio_put_pages(pages + i, left, offset); > ret = -EINVAL; > break; > } > -- Pavel Begunkov