From: Max Gurtovoy <mgurtovoy@nvidia.com>
To: Xie Yongji <xieyongji@bytedance.com>, <mst@redhat.com>,
<jasowang@redhat.com>, <stefanha@redhat.com>
Cc: <virtualization@lists.linux-foundation.org>,
<linux-block@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5] virtio-blk: Add validation for block size in config space
Date: Mon, 23 Aug 2021 02:17:21 +0300 [thread overview]
Message-ID: <e6ab104e-a18b-3f17-9cd8-6a6b689b56b4@nvidia.com> (raw)
In-Reply-To: <20210809101609.148-1-xieyongji@bytedance.com>
On 8/9/2021 1:16 PM, Xie Yongji wrote:
> An untrusted device might presents an invalid block size
> in configuration space. This tries to add validation for it
> in the validate callback and clear the VIRTIO_BLK_F_BLK_SIZE
> feature bit if the value is out of the supported range.
This is not clear to me. What is untrusted device ? is it a buggy device ?
What is the return value for the blk_size in this case that you try to
override ?
>
> And we also double check the value in virtblk_probe() in
> case that it's changed after the validation.
>
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> ---
> drivers/block/virtio_blk.c | 39 +++++++++++++++++++++++++++++++++------
> 1 file changed, 33 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 4b49df2dfd23..afb37aac09e8 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -692,6 +692,28 @@ static const struct blk_mq_ops virtio_mq_ops = {
> static unsigned int virtblk_queue_depth;
> module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
>
> +static int virtblk_validate(struct virtio_device *vdev)
> +{
> + u32 blk_size;
> +
> + if (!vdev->config->get) {
> + dev_err(&vdev->dev, "%s failure: config access disabled\n",
> + __func__);
> + return -EINVAL;
> + }
> +
> + if (!virtio_has_feature(vdev, VIRTIO_BLK_F_BLK_SIZE))
> + return 0;
> +
> + blk_size = virtio_cread32(vdev,
> + offsetof(struct virtio_blk_config, blk_size));
> +
> + if (blk_size < SECTOR_SIZE || blk_size > PAGE_SIZE)
> + __virtio_clear_bit(vdev, VIRTIO_BLK_F_BLK_SIZE);
is it PAGE_SIZE or SZ_4K ?
Do we support a 64K blk size (PPC PAGE_SIZE)
> +
> + return 0;
> +}
> +
> static int virtblk_probe(struct virtio_device *vdev)
> {
> struct virtio_blk *vblk;
> @@ -703,12 +725,6 @@ static int virtblk_probe(struct virtio_device *vdev)
> u8 physical_block_exp, alignment_offset;
> unsigned int queue_depth;
>
> - if (!vdev->config->get) {
> - dev_err(&vdev->dev, "%s failure: config access disabled\n",
> - __func__);
> - return -EINVAL;
> - }
> -
> err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
> GFP_KERNEL);
> if (err < 0)
> @@ -823,6 +839,14 @@ static int virtblk_probe(struct virtio_device *vdev)
> else
> blk_size = queue_logical_block_size(q);
>
> + if (unlikely(blk_size < SECTOR_SIZE || blk_size > PAGE_SIZE)) {
> + dev_err(&vdev->dev,
> + "block size is changed unexpectedly, now is %u\n",
> + blk_size);
> + err = -EINVAL;
> + goto err_cleanup_disk;
> + }
> +
> /* Use topology information if available */
> err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
> struct virtio_blk_config, physical_block_exp,
> @@ -881,6 +905,8 @@ static int virtblk_probe(struct virtio_device *vdev)
> device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
> return 0;
>
> +err_cleanup_disk:
> + blk_cleanup_disk(vblk->disk);
> out_free_tags:
> blk_mq_free_tag_set(&vblk->tag_set);
> out_free_vq:
> @@ -983,6 +1009,7 @@ static struct virtio_driver virtio_blk = {
> .driver.name = KBUILD_MODNAME,
> .driver.owner = THIS_MODULE,
> .id_table = id_table,
> + .validate = virtblk_validate,
> .probe = virtblk_probe,
> .remove = virtblk_remove,
> .config_changed = virtblk_config_changed,
next prev parent reply other threads:[~2021-08-22 23:17 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-09 10:16 [PATCH v5] virtio-blk: Add validation for block size in config space Xie Yongji
2021-08-10 3:05 ` Jason Wang
2021-08-10 4:59 ` Yongji Xie
2021-08-10 6:59 ` Jason Wang
2021-08-22 23:17 ` Max Gurtovoy [this message]
2021-08-23 4:31 ` Yongji Xie
2021-08-23 8:07 ` Max Gurtovoy
2021-08-23 8:35 ` Yongji Xie
2021-08-23 9:04 ` Max Gurtovoy
2021-08-23 9:27 ` Yongji Xie
2021-08-23 9:38 ` Max Gurtovoy
2021-08-23 10:33 ` Yongji Xie
2021-08-23 10:45 ` Max Gurtovoy
2021-08-23 11:41 ` Yongji Xie
2021-08-23 12:13 ` Michael S. Tsirkin
2021-08-23 12:40 ` Yongji Xie
2021-08-23 16:02 ` Michael S. Tsirkin
2021-08-23 22:31 ` Max Gurtovoy
2021-08-24 2:47 ` Jason Wang
2021-08-24 10:11 ` Max Gurtovoy
2021-08-24 12:52 ` Yongji Xie
2021-08-24 13:30 ` Max Gurtovoy
2021-08-24 13:38 ` Yongji Xie
2021-08-24 13:48 ` Max Gurtovoy
2021-10-04 15:27 ` Michael S. Tsirkin
2021-10-04 15:39 ` Michael S. Tsirkin
2021-10-05 15:52 ` Yongji Xie
2021-10-05 10:42 ` Michael S. Tsirkin
2021-10-05 15:45 ` Yongji Xie
2021-10-05 18:26 ` Martin K. Petersen
2021-10-11 11:40 ` Christoph Hellwig
2021-10-13 12:21 ` Michael S. Tsirkin
2021-10-13 12:34 ` Yongji Xie
2021-10-13 12:51 ` Michael S. Tsirkin
2021-10-13 12:59 ` Yongji Xie
2021-10-05 15:24 ` Yongji Xie
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