diff --git a/api/krusty/fnplugin_test.go b/api/krusty/fnplugin_test.go
index e4d5fa83bd5..0422b8f51a2 100644
--- a/api/krusty/fnplugin_test.go
+++ b/api/krusty/fnplugin_test.go
@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	. "sigs.k8s.io/kustomize/api/krusty"
 	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
@@ -630,3 +631,181 @@ metadata:
   name: env
 `)
 }
+
+func TestFnContainerMounts(t *testing.T) {
+	skipIfNoDocker(t)
+
+	th := kusttest_test.MakeHarness(t)
+	o := th.MakeOptionsPluginsEnabled()
+	fSys := filesys.MakeFsOnDisk()
+	b := MakeKustomizer(&o)
+	tmpDir, err := filesys.NewTmpConfirmedDir()
+	assert.NoError(t, err)
+
+	path, err := os.Getwd()
+	assert.NoError(t, err)
+	chartPath := filepath.Join(path, "testdata", "charts")
+
+	assert.NoError(t, fSys.WriteFile(filepath.Join(tmpDir.String(), "kustomization.yaml"), []byte(`
+generators:
+  - |-
+    apiVersion: v1alpha1
+    kind: RenderHelmChart
+    metadata:
+      name: demo
+      annotations:
+        config.kubernetes.io/function: |
+          container:
+            image: gcr.io/kpt-fn/render-helm-chart:v0.1.0
+            mounts:
+            - type: "bind"
+              src: "`+chartPath+`"
+              dst: "/tmp/charts"
+    helmCharts:
+    - name: helloworld-chart
+      releaseName: test
+      valuesFile: /tmp/charts/helloworld-values/values.yaml
+`)))
+	m, err := b.Run(
+		fSys,
+		tmpDir.String())
+	assert.NoError(t, err)
+	yml, err := m.AsYaml()
+	assert.NoError(t, err)
+	assert.Equal(t, `apiVersion: v1
+kind: ServiceAccount
+metadata:
+  labels:
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/managed-by: Helm
+    app.kubernetes.io/name: helloworld-chart
+    app.kubernetes.io/version: 1.16.0
+    helm.sh/chart: helloworld-chart-0.1.0
+  name: test-helloworld-chart
+---
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/managed-by: Helm
+    app.kubernetes.io/name: helloworld-chart
+    app.kubernetes.io/version: 1.16.0
+    helm.sh/chart: helloworld-chart-0.1.0
+  name: test-helloworld-chart
+spec:
+  ports:
+  - name: http
+    port: 80
+    protocol: TCP
+    targetPort: http
+  selector:
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/name: helloworld-chart
+  type: ClusterIP
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/managed-by: Helm
+    app.kubernetes.io/name: helloworld-chart
+    app.kubernetes.io/version: 1.16.0
+    helm.sh/chart: helloworld-chart-0.1.0
+  name: test-helloworld-chart
+spec:
+  replicas: 5
+  selector:
+    matchLabels:
+      app.kubernetes.io/instance: test
+      app.kubernetes.io/name: helloworld-chart
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/instance: test
+        app.kubernetes.io/name: helloworld-chart
+    spec:
+      containers:
+      - image: nginx:1.16.0
+        imagePullPolicy: Always
+        livenessProbe:
+          httpGet:
+            path: /
+            port: http
+        name: helloworld-chart
+        ports:
+        - containerPort: 80
+          name: http
+          protocol: TCP
+        readinessProbe:
+          httpGet:
+            path: /
+            port: http
+        resources: {}
+        securityContext: {}
+      securityContext: {}
+      serviceAccountName: test-helloworld-chart
+---
+apiVersion: v1
+kind: Pod
+metadata:
+  annotations:
+    helm.sh/hook: test-success
+  labels:
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/managed-by: Helm
+    app.kubernetes.io/name: helloworld-chart
+    app.kubernetes.io/version: 1.16.0
+    helm.sh/chart: helloworld-chart-0.1.0
+  name: test-helloworld-chart-test-connection
+spec:
+  containers:
+  - args:
+    - test-helloworld-chart:80
+    command:
+    - wget
+    image: busybox
+    name: wget
+  restartPolicy: Never
+`, string(yml))
+
+	assert.NoError(t, fSys.RemoveAll(tmpDir.String()))
+}
+
+func TestFnContainerMountsLoadRestrictions(t *testing.T) {
+	skipIfNoDocker(t)
+
+	th := kusttest_test.MakeHarness(t)
+	o := th.MakeOptionsPluginsEnabled()
+	fSys := filesys.MakeFsOnDisk()
+	b := MakeKustomizer(&o)
+	tmpDir, err := filesys.NewTmpConfirmedDir()
+	assert.NoError(t, err)
+
+	path, err := os.Getwd()
+	assert.NoError(t, err)
+	chartPath := filepath.Join("../", path, "testdata", "charts")
+
+	assert.NoError(t, fSys.WriteFile(filepath.Join(tmpDir.String(), "kustomization.yaml"), []byte(`
+generators:
+  - |-
+    apiVersion: v1alpha1
+    kind: RenderHelmChart
+    metadata:
+      name: demo
+      annotations:
+        config.kubernetes.io/function: |
+          container:
+            image: gcr.io/kpt-fn/render-helm-chart:v0.1.0
+            mounts:
+            - type: "bind"
+              src: "`+chartPath+`"
+              dst: "/tmp/charts"
+`)))
+	_, err = b.Run(
+		fSys,
+		tmpDir.String())
+	assert.Error(t, err)
+	assert.Equal(t, err.Error(), "couldn't execute function: declarative mount paths must be under the current directory")
+}
diff --git a/api/krusty/testdata/charts/helloworld-chart/Chart.yaml b/api/krusty/testdata/charts/helloworld-chart/Chart.yaml
new file mode 100644
index 00000000000..de4012af9da
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/Chart.yaml
@@ -0,0 +1,6 @@
+apiVersion: v2
+name: helloworld-chart
+description: A Helm chart for Kubernetes
+type: application
+version: 0.1.0
+appVersion: 1.16.0
diff --git a/api/krusty/testdata/charts/helloworld-chart/templates/NOTES.txt b/api/krusty/testdata/charts/helloworld-chart/templates/NOTES.txt
new file mode 100644
index 00000000000..af17e53fbc9
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/templates/NOTES.txt
@@ -0,0 +1,21 @@
+1. Get the application URL by running these commands:
+{{- if .Values.ingress.enabled }}
+{{- range $host := .Values.ingress.hosts }}
+  {{- range .paths }}
+  http{{ if $.Values.ingress.tls }}s{{ end }}://{{ $host.host }}{{ . }}
+  {{- end }}
+{{- end }}
+{{- else if contains "NodePort" .Values.service.type }}
+  export NODE_PORT=$(kubectl get --namespace {{ .Release.Namespace }} -o jsonpath="{.spec.ports[0].nodePort}" services {{ include "helloworld-chart.fullname" . }})
+  export NODE_IP=$(kubectl get nodes --namespace {{ .Release.Namespace }} -o jsonpath="{.items[0].status.addresses[0].address}")
+  echo http://$NODE_IP:$NODE_PORT
+{{- else if contains "LoadBalancer" .Values.service.type }}
+     NOTE: It may take a few minutes for the LoadBalancer IP to be available.
+           You can watch the status of by running 'kubectl get --namespace {{ .Release.Namespace }} svc -w {{ include "helloworld-chart.fullname" . }}'
+  export SERVICE_IP=$(kubectl get svc --namespace {{ .Release.Namespace }} {{ include "helloworld-chart.fullname" . }} --template "{{"{{ range (index .status.loadBalancer.ingress 0) }}{{.}}{{ end }}"}}")
+  echo http://$SERVICE_IP:{{ .Values.service.port }}
+{{- else if contains "ClusterIP" .Values.service.type }}
+  export POD_NAME=$(kubectl get pods --namespace {{ .Release.Namespace }} -l "app.kubernetes.io/name={{ include "helloworld-chart.name" . }},app.kubernetes.io/instance={{ .Release.Name }}" -o jsonpath="{.items[0].metadata.name}")
+  echo "Visit http://127.0.0.1:8080 to use your application"
+  kubectl --namespace {{ .Release.Namespace }} port-forward $POD_NAME 8080:80
+{{- end }}
diff --git a/api/krusty/testdata/charts/helloworld-chart/templates/_helpers.tpl b/api/krusty/testdata/charts/helloworld-chart/templates/_helpers.tpl
new file mode 100644
index 00000000000..3a62dfa0f29
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/templates/_helpers.tpl
@@ -0,0 +1,63 @@
+{{/* vim: set filetype=mustache: */}}
+{{/*
+Expand the name of the chart.
+*/}}
+{{- define "helloworld-chart.name" -}}
+{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" -}}
+{{- end -}}
+
+{{/*
+Create a default fully qualified app name.
+We truncate at 63 chars because some Kubernetes name fields are limited to this (by the DNS naming spec).
+If release name contains chart name it will be used as a full name.
+*/}}
+{{- define "helloworld-chart.fullname" -}}
+{{- if .Values.fullnameOverride -}}
+{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" -}}
+{{- else -}}
+{{- $name := default .Chart.Name .Values.nameOverride -}}
+{{- if contains $name .Release.Name -}}
+{{- .Release.Name | trunc 63 | trimSuffix "-" -}}
+{{- else -}}
+{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" -}}
+{{- end -}}
+{{- end -}}
+{{- end -}}
+
+{{/*
+Create chart name and version as used by the chart label.
+*/}}
+{{- define "helloworld-chart.chart" -}}
+{{- printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" -}}
+{{- end -}}
+
+{{/*
+Common labels
+*/}}
+{{- define "helloworld-chart.labels" -}}
+helm.sh/chart: {{ include "helloworld-chart.chart" . }}
+{{ include "helloworld-chart.selectorLabels" . }}
+{{- if .Chart.AppVersion }}
+app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
+{{- end }}
+app.kubernetes.io/managed-by: {{ .Release.Service }}
+{{- end -}}
+
+{{/*
+Selector labels
+*/}}
+{{- define "helloworld-chart.selectorLabels" -}}
+app.kubernetes.io/name: {{ include "helloworld-chart.name" . }}
+app.kubernetes.io/instance: {{ .Release.Name }}
+{{- end -}}
+
+{{/*
+Create the name of the service account to use
+*/}}
+{{- define "helloworld-chart.serviceAccountName" -}}
+{{- if .Values.serviceAccount.create -}}
+    {{ default (include "helloworld-chart.fullname" .) .Values.serviceAccount.name }}
+{{- else -}}
+    {{ default "default" .Values.serviceAccount.name }}
+{{- end -}}
+{{- end -}}
diff --git a/api/krusty/testdata/charts/helloworld-chart/templates/deployment.yaml b/api/krusty/testdata/charts/helloworld-chart/templates/deployment.yaml
new file mode 100644
index 00000000000..ca686e89ec4
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/templates/deployment.yaml
@@ -0,0 +1,55 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: {{ include "helloworld-chart.fullname" . }}
+  labels:
+    {{- include "helloworld-chart.labels" . | nindent 4 }}
+spec:
+  replicas: {{ .Values.replicaCount }}
+  selector:
+    matchLabels:
+      {{- include "helloworld-chart.selectorLabels" . | nindent 6 }}
+  template:
+    metadata:
+      labels:
+        {{- include "helloworld-chart.selectorLabels" . | nindent 8 }}
+    spec:
+    {{- with .Values.imagePullSecrets }}
+      imagePullSecrets:
+        {{- toYaml . | nindent 8 }}
+    {{- end }}
+      serviceAccountName: {{ include "helloworld-chart.serviceAccountName" . }}
+      securityContext:
+        {{- toYaml .Values.podSecurityContext | nindent 8 }}
+      containers:
+        - name: {{ .Chart.Name }}
+          securityContext:
+            {{- toYaml .Values.securityContext | nindent 12 }}
+          image: "{{ .Values.image.repository }}:{{ .Chart.AppVersion }}"
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          ports:
+            - name: http
+              containerPort: 80
+              protocol: TCP
+          livenessProbe:
+            httpGet:
+              path: /
+              port: http
+          readinessProbe:
+            httpGet:
+              path: /
+              port: http
+          resources:
+            {{- toYaml .Values.resources | nindent 12 }}
+      {{- with .Values.nodeSelector }}
+      nodeSelector:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+    {{- with .Values.affinity }}
+      affinity:
+        {{- toYaml . | nindent 8 }}
+    {{- end }}
+    {{- with .Values.tolerations }}
+      tolerations:
+        {{- toYaml . | nindent 8 }}
+    {{- end }}
diff --git a/api/krusty/testdata/charts/helloworld-chart/templates/ingress.yaml b/api/krusty/testdata/charts/helloworld-chart/templates/ingress.yaml
new file mode 100644
index 00000000000..76e1dd91d79
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/templates/ingress.yaml
@@ -0,0 +1,41 @@
+{{- if .Values.ingress.enabled -}}
+{{- $fullName := include "helloworld-chart.fullname" . -}}
+{{- $svcPort := .Values.service.port -}}
+{{- if semverCompare ">=1.14-0" .Capabilities.KubeVersion.GitVersion -}}
+apiVersion: networking.k8s.io/v1beta1
+{{- else -}}
+apiVersion: extensions/v1beta1
+{{- end }}
+kind: Ingress
+metadata:
+  name: {{ $fullName }}
+  labels:
+    {{- include "helloworld-chart.labels" . | nindent 4 }}
+  {{- with .Values.ingress.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+spec:
+{{- if .Values.ingress.tls }}
+  tls:
+  {{- range .Values.ingress.tls }}
+    - hosts:
+      {{- range .hosts }}
+        - {{ . | quote }}
+      {{- end }}
+      secretName: {{ .secretName }}
+  {{- end }}
+{{- end }}
+  rules:
+  {{- range .Values.ingress.hosts }}
+    - host: {{ .host | quote }}
+      http:
+        paths:
+        {{- range .paths }}
+          - path: {{ . }}
+            backend:
+              serviceName: {{ $fullName }}
+              servicePort: {{ $svcPort }}
+        {{- end }}
+  {{- end }}
+{{- end }}
diff --git a/api/krusty/testdata/charts/helloworld-chart/templates/service.yaml b/api/krusty/testdata/charts/helloworld-chart/templates/service.yaml
new file mode 100644
index 00000000000..a80cf8cd648
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/templates/service.yaml
@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ include "helloworld-chart.fullname" . }}
+  labels:
+    {{- include "helloworld-chart.labels" . | nindent 4 }}
+spec:
+  type: {{ .Values.service.type }}
+  ports:
+    - port: {{ .Values.service.port }}
+      targetPort: http
+      protocol: TCP
+      name: http
+  selector:
+    {{- include "helloworld-chart.selectorLabels" . | nindent 4 }}
diff --git a/api/krusty/testdata/charts/helloworld-chart/templates/serviceaccount.yaml b/api/krusty/testdata/charts/helloworld-chart/templates/serviceaccount.yaml
new file mode 100644
index 00000000000..bf9a8e15446
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/templates/serviceaccount.yaml
@@ -0,0 +1,12 @@
+{{- if .Values.serviceAccount.create -}}
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: {{ include "helloworld-chart.serviceAccountName" . }}
+  labels:
+    {{- include "helloworld-chart.labels" . | nindent 4 }}
+  {{- with .Values.serviceAccount.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+{{- end -}}
diff --git a/api/krusty/testdata/charts/helloworld-chart/templates/tests/test-connection.yaml b/api/krusty/testdata/charts/helloworld-chart/templates/tests/test-connection.yaml
new file mode 100644
index 00000000000..a71342a0d02
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/templates/tests/test-connection.yaml
@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: "{{ include "helloworld-chart.fullname" . }}-test-connection"
+  labels:
+    {{- include "helloworld-chart.labels" . | nindent 4 }}
+  annotations:
+    "helm.sh/hook": test-success
+spec:
+  containers:
+    - name: wget
+      image: busybox
+      command: ['wget']
+      args: ['{{ include "helloworld-chart.fullname" . }}:{{ .Values.service.port }}']
+  restartPolicy: Never
diff --git a/api/krusty/testdata/charts/helloworld-chart/values.yaml b/api/krusty/testdata/charts/helloworld-chart/values.yaml
new file mode 100644
index 00000000000..e81d4bf57dd
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-chart/values.yaml
@@ -0,0 +1,27 @@
+replicaCount: 1
+image:
+  repository: nginx
+  pullPolicy: IfNotPresent
+imagePullSecrets: []
+nameOverride: ""
+fullnameOverride: ""
+serviceAccount:
+  create: true
+  annotations: {}
+  name:
+podSecurityContext: {}
+securityContext: {}
+service:
+  type: ClusterIP
+  port: 80
+ingress:
+  enabled: false
+  annotations: {}
+  hosts:
+    - host: chart-example.local
+      paths: []
+  tls: []
+resources: {}
+nodeSelector: {}
+tolerations: []
+affinity: {}
diff --git a/api/krusty/testdata/charts/helloworld-values/values.yaml b/api/krusty/testdata/charts/helloworld-values/values.yaml
new file mode 100644
index 00000000000..d178c72a8ad
--- /dev/null
+++ b/api/krusty/testdata/charts/helloworld-values/values.yaml
@@ -0,0 +1,68 @@
+# Default values for helloworld-chart.
+# This is a YAML-formatted file.
+# Declare variables to be passed into your templates.
+
+replicaCount: 5
+
+image:
+  repository: nginx
+  pullPolicy: Always
+
+imagePullSecrets: []
+nameOverride: ""
+fullnameOverride: ""
+
+serviceAccount:
+  # Specifies whether a service account should be created
+  create: true
+  # Annotations to add to the service account
+  annotations: {}
+  # The name of the service account to use.
+  # If not set and create is true, a name is generated using the fullname template
+  name:
+
+podSecurityContext: {}
+# fsGroup: 2000
+
+securityContext: {}
+  # capabilities:
+  #   drop:
+  #   - ALL
+  # readOnlyRootFilesystem: true
+  # runAsNonRoot: true
+# runAsUser: 1000
+
+service:
+  type: ClusterIP
+  port: 80
+
+ingress:
+  enabled: false
+  annotations: {}
+    # kubernetes.io/ingress.class: nginx
+  # kubernetes.io/tls-acme: "true"
+  hosts:
+    - host: chart-example.local
+      paths: []
+  tls: []
+  #  - secretName: chart-example-tls
+  #    hosts:
+  #      - chart-example.local
+
+resources: {}
+  # We usually recommend not to specify default resources and to leave this as a conscious
+  # choice for the user. This also increases chances charts run on environments with little
+  # resources, such as Minikube. If you do want to specify resources, uncomment the following
+  # lines, adjust them as necessary, and remove the curly braces after 'resources:'.
+  # limits:
+  #   cpu: 100m
+  #   memory: 128Mi
+  # requests:
+  #   cpu: 100m
+#   memory: 128Mi
+
+nodeSelector: {}
+
+tolerations: []
+
+affinity: {}
diff --git a/kyaml/fn/runtime/runtimeutil/functiontypes.go b/kyaml/fn/runtime/runtimeutil/functiontypes.go
index 83e7ff0eca0..39cb241959f 100644
--- a/kyaml/fn/runtime/runtimeutil/functiontypes.go
+++ b/kyaml/fn/runtime/runtimeutil/functiontypes.go
@@ -136,9 +136,6 @@ type FunctionSpec struct {
 
 	// ExecSpec is the spec for running a function as an executable
 	Exec ExecSpec `json:"exec,omitempty" yaml:"exec,omitempty"`
-
-	// Mounts are the storage or directories to mount into the container
-	StorageMounts []StorageMount `json:"mounts,omitempty" yaml:"mounts,omitempty"`
 }
 
 type ExecSpec struct {
@@ -208,9 +205,7 @@ func GetFunctionSpec(n *yaml.RNode) *FunctionSpec {
 	if err != nil {
 		return nil
 	}
-
 	if fn := getFunctionSpecFromAnnotation(n, meta); fn != nil {
-		fn.StorageMounts = []StorageMount{}
 		return fn
 	}
 
diff --git a/kyaml/runfn/runfn.go b/kyaml/runfn/runfn.go
index eda2c290259..c7c79eefb14 100644
--- a/kyaml/runfn/runfn.go
+++ b/kyaml/runfn/runfn.go
@@ -468,11 +468,26 @@ func (r *RunFns) ffp(spec runtimeutil.FunctionSpec, api *yaml.RNode, currentUser
 		if err != nil {
 			return nil, err
 		}
+
+		// Storage mounts can either come from kustomize fn run --mounts,
+		// or from the declarative function mounts field.
+		// In the latter case, we ensure that the mount path is subject
+		// to kustomize's load restrictions.
+		storageMounts := spec.Container.StorageMounts
+		for _, mount := range storageMounts {
+			if strings.HasPrefix(filepath.Clean(mount.Src), "../") {
+				return nil, fmt.Errorf("declarative mount paths must be under the current directory") //nolint:goerr113
+			}
+		}
+		if len(storageMounts) == 0 {
+			storageMounts = r.StorageMounts
+		}
+
 		c := container.NewContainer(
 			runtimeutil.ContainerSpec{
 				Image:         spec.Container.Image,
 				Network:       spec.Container.Network,
-				StorageMounts: r.StorageMounts,
+				StorageMounts: storageMounts,
 				Env:           spec.Container.Env,
 			},
 			uidgid,
diff --git a/plugin/builtin/hashtransformer/HashTransformer_test.go b/plugin/builtin/hashtransformer/HashTransformer_test.go
index 3d62541ac04..27972250cdf 100644
--- a/plugin/builtin/hashtransformer/HashTransformer_test.go
+++ b/plugin/builtin/hashtransformer/HashTransformer_test.go
@@ -6,7 +6,7 @@ package main_test
 import (
 	"testing"
 
-	"sigs.k8s.io/kustomize/api/testutils/kusttest"
+	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
 )
 
 func TestHashTransformer(t *testing.T) {