Re: [RFC PATCH] virtio: document virtio hardening status and TODO

[Stefano Garzarella <sgarzare@redhat.com>]

I'm not a native speaker, so the following suggestions can be wrong :-)

On Fri, Oct 14, 2022 at 12:20:37PM +0800, Jason Wang wrote:
>This patch summarizes the status of hardening and TODO of hardening
>virtio core and drivers.
>
>Signed-off-by: Jason Wang <jasowang@redhat.com>
>---
> Documentation/security/virtio/core.rst | 49 ++++++++++++++++++++++++++
> MAINTAINERS                            |  1 +
> 2 files changed, 50 insertions(+)
> create mode 100644 Documentation/security/virtio/core.rst
>
>diff --git a/Documentation/security/virtio/core.rst b/Documentation/security/virtio/core.rst
>new file mode 100644
>index 000000000000..b8baa104d7c8
>--- /dev/null
>+++ b/Documentation/security/virtio/core.rst
>@@ -0,0 +1,49 @@
>+================
>+Virtio hardening
>+================
>+
>+The virtio core and drivers should not trust the devices. This means
>+all kinds of input from the device must be validated before being
>+used. This document summarizes the current status and TODO for this
>+validation/hardening efforts.

s/efforts/effort

>+
>+
>+Status
>+======
>+
>+The virtio core and drivers has done some basic hardening:
>+
>+* Config callback hardening: The core makes sure the config interrupt
>+  callbacks are enabled after the driver is ready and disable before
>+  the driver is removed.
>+
>+* Descriptor ring hardening: The metadata of a descriptor were copied
>+  and stored in a driver private memory that can not be accessed by the
>+  device. The eliminates the device triggerable behaviours through the

s/The/This ? (not sure)
)
>+  descriptor ring.
>+
>+* Device configuration space validation: Some of the virtio drivers
>+  validates the fields of device configuration space before try to use

s/validates/validate

>+  them.
>+
>+
>+TODO
>+====
>+
>+* Input buffer length validation: The virtio core needs to validate
>+  the input buffer length validation before passing them to individual

Remove "validation"?

>+  virtio drivers.
>+
>+* Virtqueue callback hardening: The virtio core (or with the help of
>+  the drivers) should guarantee that the virtqueue callbacks should not
>+  be triggered before the driver is ready or after the driver is
>+  removed.
>+
>+* Transport specific data validation: The virtio transport driver should
>+  validate the virtio transport specific data provided by the device
>+  before trying to use them in the probing.

s/in the probing/during the probe   ?

>+
>+* Device specific validation: Driver should validate the device specific
>+  metadata before being used by a specific subsystem.
>+
>+
>diff --git a/MAINTAINERS b/MAINTAINERS
>index 673b9f9b8d8a..b33cc5c751c1 100644
>--- a/MAINTAINERS
>+++ b/MAINTAINERS
>@@ -21516,6 +21516,7 @@ S:	Maintained
> F:	Documentation/ABI/testing/sysfs-bus-vdpa
> F:	Documentation/ABI/testing/sysfs-class-vduse
> F:	Documentation/devicetree/bindings/virtio/
>+F:	Documentation/security/virtio/core.rst
> F:	drivers/block/virtio_blk.c
> F:	drivers/crypto/virtio/
> F:	drivers/net/virtio_net.c
>-- 
>2.25.1
>

Thanks,
Stefano