在 2021/8/10 下午12:59, Yongji Xie 写道:
On Tue, Aug 10, 2021 at 11:05 AM Jason Wang <jasowang@xxxxxxxxxx> wrote:
在 2021/8/9 下午6:16, Xie Yongji 写道:
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.
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@xxxxxxxxxxxxx>
---
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);
I wonder if it's better to just fail here as what we did for probe().
Looks like we don't need to do that since we already clear the
VIRTIO_BLK_F_BLK_SIZE to tell the device that we don't use the block
size in configuration space. Just like what we did in
virtnet_validate().
Thanks,
Yongji
Ok, so
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
