dynamic resource allocation: add "compromised resource driver plugin"

This discusses the effect of attacking the resource driver in addition
or instead of kubelet.

Author: pohly

keps/sig-node/3063-dynamic-resource-allocation/README.md

@@ -84,6 +84,7 @@ SIG Architecture for cross-cutting KEPs).
   - [Risks and Mitigations](#risks-and-mitigations)
     - [Feature not used](#feature-not-used)
     - [Compromised node](#compromised-node)
+    - [Compromised resource driver plugin](#compromised-resource-driver-plugin)
     - [User permissions and quotas](#user-permissions-and-quotas)
     - [Usability](#usability)
 - [Design Details](#design-details)
@@ -576,6 +577,31 @@ driver vendor. Solutions like Akri which establish their own control plane and
 then communicate with Kubernetes through the device plugin API already need to
 address this.
 
+#### Compromised resource driver plugin
+
+This is the result of an attack against the resource driver, either from a
+container which uses a resource exposed by the driver, a compromised kubelet
+which interacts with the plugin, or through a successful attack against the
+node which led to root access.
+
+The resource driver plugin only needs read access to objects described in this
+KEP, so compromising it does not interfere with dynamic resource allocation for
+other drivers. It may need write access for [CRDs that communicate or
+coordinate resource
+availability](#implementing-a-plugin-for-node-resources). This could be used to
+attack scheduling involving the driver as outlined in the previous section.
+
+A resource driver may need root access on the node to manage
+hardware. Attacking the driver therefore may lead to root privilege
+escalation. Ideally, driver authors should try to avoid depending on root
+permissions and instead use capabilities or special permissions for the kernel
+APIs that they depend on.
+
+A resource driver may also need privileged access to remote services to manage
+network-attached devices. Resource driver vendors and cluster administrators
+have to consider what the effect of a compromise could be for that and how such
+privileges could get revoked.
+
 #### User permissions and quotas
 
 Similar to generic ephemeral inline volumes, the [ephemeral resource use