Re: [External] [UNIKRAFT PATCH 2/2] plat/virtio: Add error check for tag name

["Jung, Alexander (Student)" <a.jung@xxxxxxxxxxxxxxx>]

Reviewed-by: Alexander Jung <a.jung@xxxxxxxxxxx>

> On 8. Jan 2021, at 10:00, Sharan Santhanam <sharan.santhanam@xxxxxxxxx> wrote:
> 
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> attachments.
> 
> During virtio-9p configuration get we check for error while getting
> the tag length but not the tag. The patch adds this check
> 
> Signed-off-by: Sharan Santhanam <sharan.santhanam@xxxxxxxxx>
> ---
> plat/drivers/virtio/virtio_9p.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/plat/drivers/virtio/virtio_9p.c b/plat/drivers/virtio/virtio_9p.c
> index 7bd99b8d..a783eba2 100644
> --- a/plat/drivers/virtio/virtio_9p.c
> +++ b/plat/drivers/virtio/virtio_9p.c
> @@ -359,14 +359,23 @@ static int virtio_9p_feature_negotiate(struct 
> virtio_9p_device *d)
>                goto out;
>        }
> 
> -       virtio_config_get(d->vdev,
> +
> +       if (virtio_config_get(d->vdev,
>                          __offsetof(struct virtio_9p_config, tag),
> -                         d->tag, tag_len, 1);
> +                         d->tag, tag_len, 1) < 0) {
> +               uk_pr_err(DRIVER_NAME": Failed to read the tag on the device 
> %p\n",
> +                         d);
> +               rc = -EAGAIN;
> +               goto free_mem;
> +       }
>        d->tag[tag_len] = '\0';
> 
>        d->vdev->features &= host_features;
>        virtio_feature_set(d->vdev, d->vdev->features);
> +       return 0;
> 
> +free_mem:
> +       uk_free(a, d->tag);
> out:
>        return rc;
> }
> --
> 2.20.1
> 
>