Re: [PULL] vhost: cleanups and fixes

[Kees Cook]

On Thu, Nov 1, 2018 at 2:19 PM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> The following changes since commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d:
>
>   Linux 4.19 (2018-10-22 07:37:37 +0100)
>
> are available in the Git repository at:
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git tags/for_linus
>
> for you to fetch changes up to 79f800b2e76923cd8ce0aa659cb5c019d9643bc9:
>
>   MAINTAINERS: remove reference to bogus vsock file (2018-10-24 21:16:14 -0400)
>
> ----------------------------------------------------------------
> virtio, vhost: fixes, tweaks
>
> virtio balloon page hinting support
> vhost scsi control queue
>
> misc fixes.
>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
>
> ----------------------------------------------------------------
> Bijan Mottahedeh (3):
>       vhost/scsi: Respond to control queue operations

+static void
+vhost_scsi_send_tmf_resp(struct vhost_scsi *vs,
+                          struct vhost_virtqueue *vq,
+                          int head, unsigned int out)
+{
+       struct virtio_scsi_ctrl_tmf_resp __user *resp;
+       struct virtio_scsi_ctrl_tmf_resp rsp;
+       int ret;
+
+       pr_debug("%s\n", __func__);
+       memset(&rsp, 0, sizeof(rsp));
+       rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
+       resp = vq->iov[out].iov_base;
+       ret = __copy_to_user(resp, &rsp, sizeof(rsp));

Is it actually safe to trust that iov_base has passed an earlier
access_ok() check here? Why not just use copy_to_user() instead?

-Kees

>       vhost/scsi: Extract common handling code from control queue handler
>       vhost/scsi: Use common handling code in request queue handler
>
> Greg Edwards (1):
>       vhost/scsi: truncate T10 PI iov_iter to prot_bytes
>
> LÃnaÃc Huard (1):
>       kvm_config: add CONFIG_VIRTIO_MENU
>
> Stefan Hajnoczi (1):
>       MAINTAINERS: remove reference to bogus vsock file
>
> Wei Wang (3):
>       virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT
>       mm/page_poison: expose page_poisoning_enabled to kernel modules
>       virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON
>
>  MAINTAINERS                         |   1 -
>  drivers/vhost/scsi.c                | 426 ++++++++++++++++++++++++++++--------
>  drivers/virtio/virtio_balloon.c     | 380 +++++++++++++++++++++++++++++---
>  include/uapi/linux/virtio_balloon.h |   8 +
>  kernel/configs/kvm_guest.config     |   1 +
>  mm/page_poison.c                    |   6 +
>  6 files changed, 688 insertions(+), 134 deletions(-)



-- 
Kees Cook