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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90ECAC433EF for ; Tue, 12 Oct 2021 06:53:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7501E608FE for ; Tue, 12 Oct 2021 06:53:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233398AbhJLGzI (ORCPT ); Tue, 12 Oct 2021 02:55:08 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:35680 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232499AbhJLGzG (ORCPT ); Tue, 12 Oct 2021 02:55:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634021585; 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=+K4kt6jiYyHpuZzO5X/M+fhiiJdrYmcNWNspSWWUPP8=; b=I0YEVeOJ8qgKxTLZQMhBFD9A0tmBoSizFTd65hpvwRNowj3Bn7H3QjhlxGdqvc6UKIlkfB 4h53x3Hv/ZjzanRPvDo69fKpN6sTaBJ+/oSJWX4pUBHBshDObS25kVN8SFKB8a5y3PCiYT Nod/SBcKPSksEBz8dlZvcmELlQmoQRE= 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-563-lX42bIKgOCOkpdi63T3AdQ-1; Tue, 12 Oct 2021 02:53:02 -0400 X-MC-Unique: lX42bIKgOCOkpdi63T3AdQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id ED362824FBB; Tue, 12 Oct 2021 06:52:36 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-111.pek2.redhat.com [10.72.13.111]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4949E5F4EA; Tue, 12 Oct 2021 06:52:33 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, f.hetzelt@tu-berlin.de, david.kaplan@amd.com, konrad.wilk@oracle.com, Paolo Bonzini , Stefan Hajnoczi , Stefano Garzarella Subject: [PATCH V2 01/12] virtio-blk: validate num_queues during probe Date: Tue, 12 Oct 2021 14:52:16 +0800 Message-Id: <20211012065227.9953-2-jasowang@redhat.com> In-Reply-To: <20211012065227.9953-1-jasowang@redhat.com> References: <20211012065227.9953-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If an untrusted device neogitates BLK_F_MQ but advertises a zero num_queues, the driver may end up trying to allocating zero size buffers where ZERO_SIZE_PTR is returned which may pass the checking against the NULL. This will lead unexpected results. Fixing this by using single queue if num_queues is zero. Cc: Paolo Bonzini Cc: Stefan Hajnoczi Cc: Stefano Garzarella Reviewed-by: Stefan Hajnoczi Signed-off-by: Jason Wang --- drivers/block/virtio_blk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 9b3bd083b411..9deff01a38cb 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -495,7 +495,8 @@ static int init_vq(struct virtio_blk *vblk) err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, struct virtio_blk_config, num_queues, &num_vqs); - if (err) + /* We need at least one virtqueue */ + if (err || !num_vqs) num_vqs = 1; num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); -- 2.25.1