Validate PSP allowedProcMountTypes

pkg/apis/core/validation/validation.go

@@ -5234,8 +5234,8 @@ func ValidateSecurityContext(sc *core.SecurityContext, fldPath *field.Path) fiel
 	}
 
 	if sc.ProcMount != nil {
-		if err := IsValidProcMount(*sc.ProcMount); err != nil {
-			allErrs = append(allErrs, field.NotSupported(fldPath.Child("procMount"), *sc.ProcMount, []string{string(core.DefaultProcMount), string(core.UnmaskedProcMount)}))
+		if err := ValidateProcMountType(fldPath.Child("procMount"), *sc.ProcMount); err != nil {
+			allErrs = append(allErrs, err)
 		}
 	}
 
@@ -5336,13 +5336,12 @@ func IsDecremented(update, old *int32) bool {
 	return *update < *old
 }
 
-// IsValidProcMount tests that the argument is a valid ProcMountType.
-func IsValidProcMount(procMountType core.ProcMountType) error {
+// ValidateProcMountType tests that the argument is a valid ProcMountType.
+func ValidateProcMountType(fldPath *field.Path, procMountType core.ProcMountType) *field.Error {
 	switch procMountType {
-	case core.DefaultProcMount:
-	case core.UnmaskedProcMount:
+	case core.DefaultProcMount, core.UnmaskedProcMount:
+		return nil
 	default:
-		return fmt.Errorf("unsupported ProcMount type %s", procMountType)
+		return field.NotSupported(fldPath, procMountType, []string{string(core.DefaultProcMount), string(core.UnmaskedProcMount)})
 	}
-	return nil
 }

pkg/apis/policy/validation/validation.go

@@ -121,6 +121,7 @@ func ValidatePodSecurityPolicySpec(spec *policy.PodSecurityPolicySpec, fldPath *
 	allErrs = append(allErrs, validatePSPCapsAgainstDrops(spec.RequiredDropCapabilities, spec.DefaultAddCapabilities, field.NewPath("defaultAddCapabilities"))...)
 	allErrs = append(allErrs, validatePSPCapsAgainstDrops(spec.RequiredDropCapabilities, spec.AllowedCapabilities, field.NewPath("allowedCapabilities"))...)
 	allErrs = append(allErrs, validatePSPDefaultAllowPrivilegeEscalation(fldPath.Child("defaultAllowPrivilegeEscalation"), spec.DefaultAllowPrivilegeEscalation, spec.AllowPrivilegeEscalation)...)
+	allErrs = append(allErrs, validatePSPAllowedProcMountTypes(fldPath.Child("allowedProcMountTypes"), spec.AllowedProcMountTypes)...)
 	allErrs = append(allErrs, validatePSPAllowedHostPaths(fldPath.Child("allowedHostPaths"), spec.AllowedHostPaths)...)
 	allErrs = append(allErrs, validatePSPAllowedFlexVolumes(fldPath.Child("allowedFlexVolumes"), spec.AllowedFlexVolumes)...)
 	allErrs = append(allErrs, validatePodSecurityPolicySysctls(fldPath.Child("allowedUnsafeSysctls"), spec.AllowedUnsafeSysctls)...)
@@ -328,6 +329,17 @@ func validatePSPDefaultAllowPrivilegeEscalation(fldPath *field.Path, defaultAllo
 	return allErrs
 }
 
+// validatePSPAllowedProcMountTypes validates the DefaultAllowPrivilegeEscalation field against the AllowPrivilegeEscalation field of a PodSecurityPolicy.
+func validatePSPAllowedProcMountTypes(fldPath *field.Path, allowedProcMountTypes []core.ProcMountType) field.ErrorList {
+	allErrs := field.ErrorList{}
+	for i, procMountType := range allowedProcMountTypes {
+		if err := apivalidation.ValidateProcMountType(fldPath.Index(i), procMountType); err != nil {
+			allErrs = append(allErrs, err)
+		}
+	}
+	return allErrs
+}
+
 const sysctlPatternSegmentFmt string = "([a-z0-9][-_a-z0-9]*)?[a-z0-9*]"
 const SysctlPatternFmt string = "(" + apivalidation.SysctlSegmentFmt + "\\.)*" + sysctlPatternSegmentFmt
 

pkg/apis/policy/validation/validation_test.go

@@ -384,6 +384,9 @@ func TestValidatePodSecurityPolicy(t *testing.T) {
 	nonEmptyFlexVolumes := validPSP()
 	nonEmptyFlexVolumes.Spec.AllowedFlexVolumes = []policy.AllowedFlexVolume{{Driver: "example/driver"}}
 
+	invalidProcMount := validPSP()
+	invalidProcMount.Spec.AllowedProcMountTypes = []api.ProcMountType{api.ProcMountType("bogus")}
+
 	type testCase struct {
 		psp         *policy.PodSecurityPolicy
 		errorType   field.ErrorType
@@ -550,6 +553,11 @@ func TestValidatePodSecurityPolicy(t *testing.T) {
 			errorType:   field.ErrorTypeRequired,
 			errorDetail: "must specify a driver",
 		},
+		"invalid allowedProcMountTypes": {
+			psp:         invalidProcMount,
+			errorType:   field.ErrorTypeNotSupported,
+			errorDetail: `supported values: "Default", "Unmasked"`,
+		},
 	}
 
 	for k, v := range errorCases {
@@ -643,6 +651,10 @@ func TestValidatePodSecurityPolicy(t *testing.T) {
 	flexvolumeWhenAllVolumesAllowed.Spec.AllowedFlexVolumes = []policy.AllowedFlexVolume{
 		{Driver: "example/driver2"},
 	}
+
+	validProcMount := validPSP()
+	validProcMount.Spec.AllowedProcMountTypes = []api.ProcMountType{api.DefaultProcMount, api.UnmaskedProcMount}
+
 	successCases := map[string]struct {
 		psp *policy.PodSecurityPolicy
 	}{
@@ -682,6 +694,9 @@ func TestValidatePodSecurityPolicy(t *testing.T) {
 		"allow white-listed flexVolume when all volumes are allowed": {
 			psp: flexvolumeWhenAllVolumesAllowed,
 		},
+		"valid allowedProcMountTypes": {
+			psp: validProcMount,
+		},
 	}
 
 	for k, v := range successCases {