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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 F0EF3C433ED for ; Fri, 23 Apr 2021 08:11:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDECB61181 for ; Fri, 23 Apr 2021 08:11:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241374AbhDWILk (ORCPT ); Fri, 23 Apr 2021 04:11:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20807 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241496AbhDWILd (ORCPT ); Fri, 23 Apr 2021 04:11:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619165456; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AbiiXanJPfz96ay/qiIqUUYDY4TZVIjkqLicSiV3UY4=; b=PdAj7uRMkFyjBpb61HP7AkNExvTqCQTmhpqxrbAT+tRoqHG2Drf1Pu7rnIZFP4xgZUOChp EgejjoKroSa4wYXfF2yNDB7ojU1f5jMpfIOPNFvAv7AIAMkzZQvIC1Gzr1a/AZKd4tKoqW YdoGh4XfR3c7nShAmtfXvgvQp2CpsKk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-327-7tMPmJ3NOxm71u2hmQMyvw-1; Fri, 23 Apr 2021 04:10:52 -0400 X-MC-Unique: 7tMPmJ3NOxm71u2hmQMyvw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EE8F318397AA; Fri, 23 Apr 2021 08:10:50 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-225.pek2.redhat.com [10.72.13.225]) by smtp.corp.redhat.com (Postfix) with ESMTP id D30365C5E0; Fri, 23 Apr 2021 08:10:35 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, xieyongji@bytedance.com, stefanha@redhat.com, file@sect.tu-berlin.de, ashish.kalra@amd.com, konrad.wilk@oracle.com, kvm@vger.kernel.org, hch@infradead.org Subject: [RFC PATCH V2 4/7] virtio_ring: secure handling of mapping errors Date: Fri, 23 Apr 2021 16:09:39 +0800 Message-Id: <20210423080942.2997-5-jasowang@redhat.com> In-Reply-To: <20210423080942.2997-1-jasowang@redhat.com> References: <20210423080942.2997-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We should not depend on the DMA address, length and flag of descriptor table since they could be wrote with arbitrary value by the device. So this patch switches to use the stored one in desc_extra. Note that the indirect descriptors are fine since they are read-only streaming mappings. Signed-off-by: Jason Wang --- drivers/virtio/virtio_ring.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 0cdd965dba58..5509c2643fb1 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1213,13 +1213,16 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, unmap_release: err_idx = i; i = head; + curr = vq->free_head; vq->packed.avail_used_flags = avail_used_flags; for (n = 0; n < total_sg; n++) { if (i == err_idx) break; - vring_unmap_desc_packed(vq, &desc[i]); + vring_unmap_state_packed(vq, + &vq->packed.desc_extra[curr]); + curr = vq->packed.desc_extra[curr].next; i++; if (i >= vq->packed.vring.num) i = 0; -- 2.25.1