From: Yongji Xie <xieyongji@bytedance.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
"Jason Wang" <jasowang@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Stefano Garzarella" <sgarzare@redhat.com>,
"Parav Pandit" <parav@nvidia.com>,
"Christoph Hellwig" <hch@infradead.org>,
"Christian Brauner" <christian.brauner@canonical.com>,
"Randy Dunlap" <rdunlap@infradead.org>,
"Matthew Wilcox" <willy@infradead.org>,
viro@zeniv.linux.org.uk, "Jens Axboe" <axboe@kernel.dk>,
bcrl@kvack.org, "Jonathan Corbet" <corbet@lwn.net>,
"Mika Penttilä" <mika.penttila@nextfour.com>,
joro@8bytes.org,
virtualization <virtualization@lists.linux-foundation.org>,
netdev@vger.kernel.org, kvm <kvm@vger.kernel.org>,
linux-fsdevel@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Re: [PATCH v7 04/12] virtio-blk: Add validation for block size in config space
Date: Thu, 20 May 2021 13:25:16 +0800 [thread overview]
Message-ID: <CACycT3veubBFCg9omxLDJJFP7B7QH8++Q+tKmb_M_hmNS45cmw@mail.gmail.com> (raw)
In-Reply-To: <20210519144206.GF32682@kadam>
On Wed, May 19, 2021 at 10:42 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Wed, May 19, 2021 at 09:39:20PM +0800, Yongji Xie wrote:
> > On Mon, May 17, 2021 at 5:56 PM Xie Yongji <xieyongji@bytedance.com> wrote:
> > >
> > > This ensures that we will not use an invalid block size
> > > in config space (might come from an untrusted device).
>
> I looked at if I should add this as an untrusted function so that Smatch
> could find these sorts of bugs but this is reading data from the host so
> there has to be some level of trust...
>
It would be great if Smatch could detect this case if possible. The
data might be trusted in traditional VM cases. But now the data can be
read from a userspace daemon when VDUSE is enabled.
> I should add some more untrusted data kvm functions to Smatch. Right
> now I only have kvm_register_read() and I've added kvm_read_guest_virt()
> just now.
>
> > >
> > > Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> > > ---
> > > drivers/block/virtio_blk.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> > > index ebb4d3fe803f..c848aa36d49b 100644
> > > --- a/drivers/block/virtio_blk.c
> > > +++ b/drivers/block/virtio_blk.c
> > > @@ -826,7 +826,7 @@ static int virtblk_probe(struct virtio_device *vdev)
> > > err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
> > > struct virtio_blk_config, blk_size,
> > > &blk_size);
> > > - if (!err)
> > > + if (!err && blk_size > 0 && blk_size <= max_size)
> >
> > The check here is incorrect. I will use PAGE_SIZE as the maximum
> > boundary in the new version.
>
> What does this bug look like to the user?
The kernel will panic if the block size is larger than PAGE_SIZE.
> A minimum block size of 1 seems pretty crazy. Surely the minimum should be > higher?
>
Yes, 512 is better here.
Thanks,
Yongji
next prev parent reply other threads:[~2021-05-20 5:25 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 9:55 [PATCH v7 00/12] Introduce VDUSE - vDPA Device in Userspace Xie Yongji
2021-05-17 9:55 ` [PATCH v7 01/12] iova: Export alloc_iova_fast() Xie Yongji
2021-05-26 2:36 ` Jason Wang
2021-05-26 2:43 ` Yongji Xie
2021-05-17 9:55 ` [PATCH v7 02/12] file: Export receive_fd() to modules Xie Yongji
2021-05-20 6:18 ` Al Viro
2021-05-20 6:32 ` Yongji Xie
2021-05-17 9:55 ` [PATCH v7 03/12] eventfd: Increase the recursion depth of eventfd_signal() Xie Yongji
2021-05-17 9:55 ` [PATCH v7 04/12] virtio-blk: Add validation for block size in config space Xie Yongji
2021-05-19 13:39 ` Yongji Xie
2021-05-19 14:42 ` Dan Carpenter
2021-05-20 5:25 ` Yongji Xie [this message]
2021-05-20 5:43 ` Michael S. Tsirkin
2021-05-20 7:08 ` Yongji Xie
2021-05-17 9:55 ` [PATCH v7 05/12] virtio_scsi: Add validation for residual bytes from response Xie Yongji
2021-05-26 2:41 ` Jason Wang
2021-05-17 9:55 ` [PATCH v7 06/12] vhost-iotlb: Add an opaque pointer for vhost IOTLB Xie Yongji
2021-05-17 9:55 ` [PATCH v7 07/12] vdpa: Add an opaque pointer for vdpa_config_ops.dma_map() Xie Yongji
2021-05-17 9:55 ` [PATCH v7 08/12] vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap() Xie Yongji
2021-05-17 9:55 ` [PATCH v7 09/12] vdpa: Support transferring virtual addressing during DMA mapping Xie Yongji
2021-05-17 9:55 ` [PATCH v7 10/12] vduse: Implement an MMU-based IOMMU driver Xie Yongji
2021-05-17 9:55 ` [PATCH v7 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace Xie Yongji
2021-05-20 6:28 ` Al Viro
2021-05-20 7:03 ` Yongji Xie
2021-05-27 4:12 ` Jason Wang
2021-05-27 4:57 ` Yongji Xie
2021-05-27 5:00 ` Jason Wang
2021-05-27 5:08 ` Yongji Xie
2021-05-27 5:40 ` Jason Wang
2021-05-27 7:34 ` Yongji Xie
2021-05-27 8:41 ` Jason Wang
2021-05-27 8:43 ` Jason Wang
2021-05-27 10:14 ` Yongji Xie
2021-05-28 1:33 ` Jason Wang
2021-05-28 3:54 ` Yongji Xie
2021-05-28 6:38 ` Jason Wang
2021-05-27 13:17 ` Yongji Xie
2021-05-28 2:31 ` Jason Wang
2021-05-31 4:27 ` Yongji Xie
2021-05-31 4:38 ` Jason Wang
2021-05-31 6:24 ` Yongji Xie
2021-05-31 4:56 ` Greg KH
2021-05-31 6:19 ` Yongji Xie
2021-05-31 6:32 ` Greg KH
2021-05-31 7:13 ` Yongji Xie
2021-05-17 9:55 ` [PATCH v7 12/12] Documentation: Add documentation for VDUSE Xie Yongji
2021-05-20 6:06 ` [PATCH v7 00/12] Introduce VDUSE - vDPA Device in Userspace Michael S. Tsirkin
2021-05-20 9:06 ` Yongji Xie
2021-05-25 6:40 ` Jason Wang
2021-05-25 6:48 ` Michael S. Tsirkin
2021-05-25 7:11 ` Jason Wang
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