Bug Report

General Information

• Environment description - Any environment
• Kernel version - Not relevant
• Orchestration system version in use - Not relevant

To Reproduce

1. Modify make run target in KubeArmor's Makefile to something like below such that host policy is disabled:

   cd $(CURDIR); DEBUG=true sudo -E ./kubearmor -k8s=false -logPath=/tmp/kubearmor.log -enableKubeArmorPolicy -defaultFilePosture block -defaultCapabilitiesPosture block -defaultNetworkPosture block
   

2. Once KubeArmor is running, send the below host policy by running karmor vm policy --gRPC=:32767 add <path-to-policy> :

   apiVersion: security.kubearmor.com/v1
   kind: KubeArmorHostPolicy
   metadata:
     name: hsp-block-sleep
   spec:
     severity: 10
     message: "sleep was attempted to be executed"
     tags:
     - ALERT
     nodeSelector:
       matchLabels:
         kubearmor.io/hostname: '*'
     process:
       matchPaths:
       - path: /usr/bin/sleep
     action:
       Block

   You'll see that KubeArmor panics and dies with the below log:

        panic: runtime error: invalid memory address or nil pointer dereference
       [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x189052c]
   
       goroutine 424 [running]:
       github.com/kubearmor/KubeArmor/KubeArmor/policy.(*PolicyServer).HostPolicy(0xc00460c3c0, {0x1c94900?, 0xc0039e5990?}, 0xc003be38c0)
               /usr/src/KubeArmor/KubeArmor/policy/policy.go:62 +0xac
       github.com/kubearmor/KubeArmor/protobuf._PolicyService_HostPolicy_Handler({0x1c94900, 0xc00460c3c0}, {0x22822a8, 0xc00471ef60}, 0xc004689780, 0x0)
               /usr/src/KubeArmor/protobuf/policy_grpc.pb.go:203 +0x1a6
       google.golang.org/grpc.(*Server).processUnaryRPC(0xc00022d200, {0x22822a8, 0xc00471eed0}, {0x228afa0, 0xc00472d080}, 0xc0048fe000, 0xc0046086c0, 0x335bd18, 0x0)
               /go/pkg/mod/google.golang.org/[email protected]/server.go:1369 +0xdf8
       google.golang.org/grpc.(*Server).handleStream(0xc00022d200, {0x228afa0, 0xc00472d080}, 0xc0048fe000)
               /go/pkg/mod/google.golang.org/[email protected]/server.go:1780 +0xe8b
       google.golang.org/grpc.(*Server).serveStreams.func2.1()
               /go/pkg/mod/google.golang.org/[email protected]/server.go:1019 +0x8b
       created by google.golang.org/grpc.(*Server).serveStreams.func2 in goroutine 436
               /go/pkg/mod/google.golang.org/[email protected]/server.go:1030 +0x125
   
   

Similar behavior is observed when container policy is disabled.

Expected behavior

KubeArmor should not panic and just log OR send back the response that policy enforcement for this kind (KubeArmorPolicy/KubeArmorHostPolicy) is not enabled.