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Re: [Qemu-devel] [PATCH 2/3] virtio: Strictly check queue_size when addi
From: |
Amos Kong |
Subject: |
Re: [Qemu-devel] [PATCH 2/3] virtio: Strictly check queue_size when adding virtqueue |
Date: |
Thu, 16 Jun 2011 06:53:59 +0800 |
User-agent: |
Mutt/1.5.20 (2009-06-14) |
On Wed, Jun 15, 2011 at 11:36:02PM +0300, Michael S. Tsirkin wrote:
> On Wed, Jun 15, 2011 at 10:25:33PM +0800, Amos Kong wrote:
> > Qemu should abort when 'queue_size' is less than or equals to zero.
> >
> > Signed-off-by: Amos Kong <address@hidden>
>
> BTW, these patches apply upstream so should be sent to qemu-devel.
>
> > ---
> > hw/virtio.c | 3 ++-
> > 1 files changed, 2 insertions(+), 1 deletions(-)
> >
> > diff --git a/hw/virtio.c b/hw/virtio.c
> > index a3d0eee..855fe54 100644
> > --- a/hw/virtio.c
> > +++ b/hw/virtio.c
> > @@ -612,7 +612,8 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev, int
> > queue_size,
> > break;
> > }
> >
> > - if (i == VIRTIO_PCI_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE)
> > + if (i == VIRTIO_PCI_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE ||
> > + queue_size <= 0)
> > abort();
> >
> > vdev->vq[i].vring.num = queue_size;
>
> These checks are just a debugging aid - there's no way
> for the guest or user to trigger this.
> I guess it does no harm, but what are we guarding against?
> Why would anyone pass in a negative value?
It seems all exist usage of this function are all right, guest/user could not
trigger this right now.
So we don't need to fix this kind of problem?
- Re: [Qemu-devel] [PATCH 2/3] virtio: Strictly check queue_size when adding virtqueue,
Amos Kong <=