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 96C51C433F5 for ; Wed, 13 Oct 2021 10:04:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A6506101D for ; Wed, 13 Oct 2021 10:04:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239184AbhJMKGx (ORCPT ); Wed, 13 Oct 2021 06:06:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:40455 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237525AbhJMKGv (ORCPT ); Wed, 13 Oct 2021 06:06:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634119487; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=OhtK0nXUdl5AJXub6wt3SlLG8E5tzLdcIINFEk1zgkM=; b=hoyEHYV79eFTasdlFBCqwqwILw3N715NHACSPzi94d8VQeD2okB7lbOjX3VppLGJO7bGv9 fXjjG6jYQIueoACPww135Mqe1bFWaX+/FoQJbkBHp5hDEkupix4jD+h2WWWlw1AfsoCNzF D7w1ItOuRl8qDgTqMJ7mMvNvVQ08f3Y= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-62-eK5APgFIP72wlYG_MWTdTw-1; Wed, 13 Oct 2021 06:04:46 -0400 X-MC-Unique: eK5APgFIP72wlYG_MWTdTw-1 Received: by mail-wr1-f71.google.com with SMTP id 75-20020adf82d1000000b00160cbb0f800so1527513wrc.22 for ; Wed, 13 Oct 2021 03:04:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=OhtK0nXUdl5AJXub6wt3SlLG8E5tzLdcIINFEk1zgkM=; b=0//cEscaiZBW0JgvkcMGnI90J9kBRE98QUh+WEm9S3hz+hLPU/RQdcUL1L8pMs7ftn FStChjLT2h/bT/o/jI8E4RUqDYVCYFAQI0OxhTsRFm1acdhEiWyG47hwIMUL8CdKI0KK r3u1s0OOrhQbQOsGyIRM+zZQftQfg69WpLDEWbIbICkWJfc9yiSl70cnCRrjL0YxN9Mg eRCRpfGW31gsE2bj1OLx+dK1sosv4BtSgR1/kfXAnjVWSplrAF/UaNM+ldPSJgeBSdZ2 h/H8/YVrDpz9IwQQ5FvfxyIJLqKWI1yb28ZkP6g1jOdA/N63U6TRMJaGutKMu+2MbZyf fhdw== X-Gm-Message-State: AOAM533KHT1xs/YoyovFJyxN2B+iByadRBmPq0oS+VyihzDqMcyZ4SGw PV7s2wr83dy518cKRS8VC8yUbSkGxeZgrdpobKNuhz3yvHo7b+EEZ1vrlufV8CJTlOe4DnYHlI7 Sq/tcwxnkj5titeYZsl5SGmsF X-Received: by 2002:a5d:4344:: with SMTP id u4mr40366218wrr.106.1634119485498; Wed, 13 Oct 2021 03:04:45 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxGAAkxN28lCL/1rNJa4xwl0lLeA2jwCGcDEI+EhVuW39fm1FqtHtMBRNyPP8sfVmXbdTaljQ== X-Received: by 2002:a5d:4344:: with SMTP id u4mr40366199wrr.106.1634119485316; Wed, 13 Oct 2021 03:04:45 -0700 (PDT) Received: from redhat.com ([2.55.30.112]) by smtp.gmail.com with ESMTPSA id b3sm1591483wrp.52.2021.10.13.03.04.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Oct 2021 03:04:44 -0700 (PDT) Date: Wed, 13 Oct 2021 06:04:39 -0400 From: "Michael S. Tsirkin" To: Jason Wang 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: Re: [PATCH V2 01/12] virtio-blk: validate num_queues during probe Message-ID: <20211013060341-mutt-send-email-mst@kernel.org> References: <20211012065227.9953-1-jasowang@redhat.com> <20211012065227.9953-2-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211012065227.9953-2-jasowang@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 12, 2021 at 02:52:16PM +0800, Jason Wang wrote: > 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 I'd rather fail probe so we don't need to support that. > --- > 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