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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 0758EC4338F for ; Tue, 10 Aug 2021 04:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D778F6101E for ; Tue, 10 Aug 2021 04:59:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237067AbhHJE7p (ORCPT ); Tue, 10 Aug 2021 00:59:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235564AbhHJE7p (ORCPT ); Tue, 10 Aug 2021 00:59:45 -0400 Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com [IPv6:2a00:1450:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7865EC0613D3 for ; Mon, 9 Aug 2021 21:59:23 -0700 (PDT) Received: by mail-ej1-x629.google.com with SMTP id e19so33097527ejs.9 for ; Mon, 09 Aug 2021 21:59:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=hZO0FWGJSI/OPAyxmSYKNVRiGL538jyzDi1o3M9h0YY=; b=az9IIuf4LvV5E1gUiDJAMnHmhCGl441kTFEuArgXi1dxCGgvCeD3ncukC6cO6IReW8 CMKEbkH+vQbKYPCdSkXRrGFs7gwC9iwEr+thhh5P1zJQpCwhZUmRKOgBXFT6iuUtb3SL Sa/ERYw45Ey1tn7fAQ1OlnGrErYioC8bDdavLtoSZ6IPKYSoMNpQOLtuET13csRer5aE zqz74C8Cbm56Jy+h2RBa7JlWO/ki6dcU749unluyLGli8Z040kDxr89W8/UNhGFwHUyY mQBnQ7ylJ1iT0GXbI02m7aYuWAeD8O9yu31WYfp1lUE2+0IDJNbLF48NU5POnZ58CPty HKxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=hZO0FWGJSI/OPAyxmSYKNVRiGL538jyzDi1o3M9h0YY=; b=J6K3oxDZ5HdXEMr67RH27PGxDtVqmSzRi7FABLxsOYCKkNyYEjZnWXn1lDzULn+BTc 3mL9eab+4b4DUe0EdH+ZPc+/m18mqPMFEPs29acucVfI0ojtPaJ5dUZpMNXN95qhazxt z0FdpMqhGpmL6n59jNDXdUt9WEblBa8ze2BDK0ZKOzvFLDzm7iWs0T28tpx95zhwDaBp ubMfT2zkBzaJRTXH3Hmw9EgJbrmLpkcOpm1CIcza6cHOySt8SK0Ar+RWOFU9AFCoxJVx sxUTwOMSTfnl5LsQ0HdYl2DUlS7OwuBlJmWBNWHkf/wqNXTBcfoIpDVj91Qmb7Ki66Y0 Jp1A== X-Gm-Message-State: AOAM530950zJUKzMX8ii55MrdeDw+LkFHVUow+Kh19d6/nmhxZyqo/zG vPAkQOAnbA8IOhEBKnbD/TG0hiBrx/MVxT1CNEKl X-Google-Smtp-Source: ABdhPJzvFRX9YucIuizA9bbIwHFfVwAxS5dUu+C02IZQr62VEgmlzgEaZ1KwWj20s6AZdy8k+SdUk7MCY44RrSczTkw= X-Received: by 2002:a17:906:58c7:: with SMTP id e7mr25285736ejs.197.1628571562110; Mon, 09 Aug 2021 21:59:22 -0700 (PDT) MIME-Version: 1.0 References: <20210809101609.148-1-xieyongji@bytedance.com> <08366773-76b5-be73-7e32-d9ce6f6799bf@redhat.com> In-Reply-To: <08366773-76b5-be73-7e32-d9ce6f6799bf@redhat.com> From: Yongji Xie Date: Tue, 10 Aug 2021 12:59:11 +0800 Message-ID: Subject: Re: [PATCH v5] virtio-blk: Add validation for block size in config space To: Jason Wang Cc: "Michael S. Tsirkin" , Stefan Hajnoczi , virtualization , linux-block@vger.kernel.org, linux-kernel Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, Aug 10, 2021 at 11:05 AM Jason Wang wrote: > > > =E5=9C=A8 2021/8/9 =E4=B8=8B=E5=8D=886:16, Xie Yongji =E5=86=99=E9=81=93: > > An untrusted device might presents an invalid block size > > in configuration space. This tries to add validation for it > > in the validate callback and clear the VIRTIO_BLK_F_BLK_SIZE > > feature bit if the value is out of the supported range. > > > > And we also double check the value in virtblk_probe() in > > case that it's changed after the validation. > > > > Signed-off-by: Xie Yongji > > --- > > drivers/block/virtio_blk.c | 39 +++++++++++++++++++++++++++++++++----= -- > > 1 file changed, 33 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > index 4b49df2dfd23..afb37aac09e8 100644 > > --- a/drivers/block/virtio_blk.c > > +++ b/drivers/block/virtio_blk.c > > @@ -692,6 +692,28 @@ static const struct blk_mq_ops virtio_mq_ops =3D { > > static unsigned int virtblk_queue_depth; > > module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); > > > > +static int virtblk_validate(struct virtio_device *vdev) > > +{ > > + u32 blk_size; > > + > > + if (!vdev->config->get) { > > + dev_err(&vdev->dev, "%s failure: config access disabled\n= ", > > + __func__); > > + return -EINVAL; > > + } > > + > > + if (!virtio_has_feature(vdev, VIRTIO_BLK_F_BLK_SIZE)) > > + return 0; > > + > > + blk_size =3D virtio_cread32(vdev, > > + offsetof(struct virtio_blk_config, blk_size)); > > + > > + if (blk_size < SECTOR_SIZE || blk_size > PAGE_SIZE) > > + __virtio_clear_bit(vdev, VIRTIO_BLK_F_BLK_SIZE); > > > I wonder if it's better to just fail here as what we did for probe(). > Looks like we don't need to do that since we already clear the VIRTIO_BLK_F_BLK_SIZE to tell the device that we don't use the block size in configuration space. Just like what we did in virtnet_validate(). Thanks, Yongji