Merge pull request #690 from elezar/ignore-ldconfig-option

Only allow host-relative LDConfig paths

cmd/nvidia-container-runtime-hook/container_config.go

@@ -157,7 +157,7 @@ func getDevicesFromEnvvar(containerImage image.CUDA, swarmResourceEnvvars []stri
 	return containerImage.VisibleDevicesFromEnvVar()
 }
 
-func getDevices(hookConfig *HookConfig, image image.CUDA, privileged bool) []string {
+func (hookConfig *hookConfig) getDevices(image image.CUDA, privileged bool) []string {
 	// If enabled, try and get the device list from volume mounts first
 	if hookConfig.AcceptDeviceListAsVolumeMounts {
 		devices := image.VisibleDevicesFromMounts()
@@ -197,7 +197,7 @@ func getMigDevices(image image.CUDA, envvar string) *string {
 	return &devices
 }
 
-func getImexChannels(hookConfig *HookConfig, image image.CUDA, privileged bool) []string {
+func (hookConfig *hookConfig) getImexChannels(image image.CUDA, privileged bool) []string {
 	// If enabled, try and get the device list from volume mounts first
 	if hookConfig.AcceptDeviceListAsVolumeMounts {
 		devices := image.ImexChannelsFromMounts()
@@ -217,10 +217,10 @@ func getImexChannels(hookConfig *HookConfig, image image.CUDA, privileged bool)
 	return nil
 }
 
-func (c *HookConfig) getDriverCapabilities(cudaImage image.CUDA, legacyImage bool) image.DriverCapabilities {
+func (hookConfig *hookConfig) getDriverCapabilities(cudaImage image.CUDA, legacyImage bool) image.DriverCapabilities {
 	// We use the default driver capabilities by default. This is filtered to only include the
 	// supported capabilities
-	supportedDriverCapabilities := image.NewDriverCapabilities(c.SupportedDriverCapabilities)
+	supportedDriverCapabilities := image.NewDriverCapabilities(hookConfig.SupportedDriverCapabilities)
 
 	capabilities := supportedDriverCapabilities.Intersection(image.DefaultDriverCapabilities)
 
@@ -244,10 +244,10 @@ func (c *HookConfig) getDriverCapabilities(cudaImage image.CUDA, legacyImage boo
 	return capabilities
 }
 
-func getNvidiaConfig(hookConfig *HookConfig, image image.CUDA, privileged bool) *nvidiaConfig {
+func (hookConfig *hookConfig) getNvidiaConfig(image image.CUDA, privileged bool) *nvidiaConfig {
 	legacyImage := image.IsLegacy()
 
-	devices := getDevices(hookConfig, image, privileged)
+	devices := hookConfig.getDevices(image, privileged)
 	if len(devices) == 0 {
 		// empty devices means this is not a GPU container.
 		return nil
@@ -269,7 +269,7 @@ func getNvidiaConfig(hookConfig *HookConfig, image image.CUDA, privileged bool)
 		log.Panicln("cannot set MIG_MONITOR_DEVICES in non privileged container")
 	}
 
-	imexChannels := getImexChannels(hookConfig, image, privileged)
+	imexChannels := hookConfig.getImexChannels(image, privileged)
 
 	driverCapabilities := hookConfig.getDriverCapabilities(image, legacyImage).String()
 
@@ -288,7 +288,7 @@ func getNvidiaConfig(hookConfig *HookConfig, image image.CUDA, privileged bool)
 	}
 }
 
-func getContainerConfig(hook HookConfig) (config containerConfig) {
+func (hookConfig *hookConfig) getContainerConfig() (config containerConfig) {
 	var h HookState
 	d := json.NewDecoder(os.Stdin)
 	if err := d.Decode(&h); err != nil {
@@ -305,7 +305,7 @@ func getContainerConfig(hook HookConfig) (config containerConfig) {
 	image, err := image.New(
 		image.WithEnv(s.Process.Env),
 		image.WithMounts(s.Mounts),
-		image.WithDisableRequire(hook.DisableRequire),
+		image.WithDisableRequire(hookConfig.DisableRequire),
 	)
 	if err != nil {
 		log.Panicln(err)
@@ -316,6 +316,6 @@ func getContainerConfig(hook HookConfig) (config containerConfig) {
 		Pid:    h.Pid,
 		Rootfs: s.Root.Path,
 		Image:  image,
-		Nvidia: getNvidiaConfig(&hook, image, privileged),
+		Nvidia: hookConfig.getNvidiaConfig(image, privileged),
 	}
 }

cmd/nvidia-container-runtime-hook/container_config_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/stretchr/testify/require"
 
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/config/image"
 )
 
@@ -15,7 +16,7 @@ func TestGetNvidiaConfig(t *testing.T) {
 		description    string
 		env            map[string]string
 		privileged     bool
-		hookConfig     *HookConfig
+		hookConfig     *hookConfig
 		expectedConfig *nvidiaConfig
 		expectedPanic  bool
 	}{
@@ -394,8 +395,10 @@ func TestGetNvidiaConfig(t *testing.T) {
 				image.EnvVarNvidiaDriverCapabilities: "all",
 			},
 			privileged: true,
-			hookConfig: &HookConfig{
-				SupportedDriverCapabilities: "video,display",
+			hookConfig: &hookConfig{
+				Config: &config.Config{
+					SupportedDriverCapabilities: "video,display",
+				},
 			},
 			expectedConfig: &nvidiaConfig{
 				Devices:            []string{"all"},
@@ -409,8 +412,10 @@ func TestGetNvidiaConfig(t *testing.T) {
 				image.EnvVarNvidiaDriverCapabilities: "video,display",
 			},
 			privileged: true,
-			hookConfig: &HookConfig{
-				SupportedDriverCapabilities: "video,display,compute,utility",
+			hookConfig: &hookConfig{
+				Config: &config.Config{
+					SupportedDriverCapabilities: "video,display,compute,utility",
+				},
 			},
 			expectedConfig: &nvidiaConfig{
 				Devices:            []string{"all"},
@@ -423,8 +428,10 @@ func TestGetNvidiaConfig(t *testing.T) {
 				image.EnvVarNvidiaVisibleDevices: "all",
 			},
 			privileged: true,
-			hookConfig: &HookConfig{
-				SupportedDriverCapabilities: "video,display,utility,compute",
+			hookConfig: &hookConfig{
+				Config: &config.Config{
+					SupportedDriverCapabilities: "video,display,utility,compute",
+				},
 			},
 			expectedConfig: &nvidiaConfig{
 				Devices:            []string{"all"},
@@ -438,9 +445,11 @@ func TestGetNvidiaConfig(t *testing.T) {
 				"DOCKER_SWARM_RESOURCE":          "GPU1,GPU2",
 			},
 			privileged: true,
-			hookConfig: &HookConfig{
-				SwarmResource:               "DOCKER_SWARM_RESOURCE",
-				SupportedDriverCapabilities: "video,display,utility,compute",
+			hookConfig: &hookConfig{
+				Config: &config.Config{
+					SwarmResource:               "DOCKER_SWARM_RESOURCE",
+					SupportedDriverCapabilities: "video,display,utility,compute",
+				},
 			},
 			expectedConfig: &nvidiaConfig{
 				Devices:            []string{"GPU1", "GPU2"},
@@ -454,9 +463,11 @@ func TestGetNvidiaConfig(t *testing.T) {
 				"DOCKER_SWARM_RESOURCE":          "GPU1,GPU2",
 			},
 			privileged: true,
-			hookConfig: &HookConfig{
-				SwarmResource:               "NOT_DOCKER_SWARM_RESOURCE,DOCKER_SWARM_RESOURCE",
-				SupportedDriverCapabilities: "video,display,utility,compute",
+			hookConfig: &hookConfig{
+				Config: &config.Config{
+					SwarmResource:               "NOT_DOCKER_SWARM_RESOURCE,DOCKER_SWARM_RESOURCE",
+					SupportedDriverCapabilities: "video,display,utility,compute",
+				},
 			},
 			expectedConfig: &nvidiaConfig{
 				Devices:            []string{"GPU1", "GPU2"},
@@ -470,14 +481,14 @@ func TestGetNvidiaConfig(t *testing.T) {
 				image.WithEnvMap(tc.env),
 			)
 			// Wrap the call to getNvidiaConfig() in a closure.
-			var config *nvidiaConfig
+			var cfg *nvidiaConfig
 			getConfig := func() {
-				hookConfig := tc.hookConfig
-				if hookConfig == nil {
-					defaultConfig, _ := getDefaultHookConfig()
-					hookConfig = &defaultConfig
+				hookCfg := tc.hookConfig
+				if hookCfg == nil {
+					defaultConfig, _ := config.GetDefault()
+					hookCfg = &hookConfig{defaultConfig}
 				}
-				config = getNvidiaConfig(hookConfig, image, tc.privileged)
+				cfg = hookCfg.getNvidiaConfig(image, tc.privileged)
 			}
 
 			// For any tests that are expected to panic, make sure they do.
@@ -491,18 +502,18 @@ func TestGetNvidiaConfig(t *testing.T) {
 
 			// And start comparing the test results to the expected results.
 			if tc.expectedConfig == nil {
-				require.Nil(t, config, tc.description)
+				require.Nil(t, cfg, tc.description)
 				return
 			}
 
-			require.NotNil(t, config, tc.description)
+			require.NotNil(t, cfg, tc.description)
 
-			require.Equal(t, tc.expectedConfig.Devices, config.Devices)
-			require.Equal(t, tc.expectedConfig.MigConfigDevices, config.MigConfigDevices)
-			require.Equal(t, tc.expectedConfig.MigMonitorDevices, config.MigMonitorDevices)
-			require.Equal(t, tc.expectedConfig.DriverCapabilities, config.DriverCapabilities)
+			require.Equal(t, tc.expectedConfig.Devices, cfg.Devices)
+			require.Equal(t, tc.expectedConfig.MigConfigDevices, cfg.MigConfigDevices)
+			require.Equal(t, tc.expectedConfig.MigMonitorDevices, cfg.MigMonitorDevices)
+			require.Equal(t, tc.expectedConfig.DriverCapabilities, cfg.DriverCapabilities)
 
-			require.ElementsMatch(t, tc.expectedConfig.Requirements, config.Requirements)
+			require.ElementsMatch(t, tc.expectedConfig.Requirements, cfg.Requirements)
 		})
 	}
 }
@@ -612,10 +623,11 @@ func TestDeviceListSourcePriority(t *testing.T) {
 					),
 					image.WithMounts(tc.mountDevices),
 				)
-				hookConfig, _ := getDefaultHookConfig()
-				hookConfig.AcceptEnvvarUnprivileged = tc.acceptUnprivileged
-				hookConfig.AcceptDeviceListAsVolumeMounts = tc.acceptMounts
-				devices = getDevices(&hookConfig, image, tc.privileged)
+				defaultConfig, _ := config.GetDefault()
+				cfg := &hookConfig{defaultConfig}
+				cfg.AcceptEnvvarUnprivileged = tc.acceptUnprivileged
+				cfg.AcceptDeviceListAsVolumeMounts = tc.acceptMounts
+				devices = cfg.getDevices(image, tc.privileged)
 			}
 
 			// For all other tests, just grab the devices and check the results
@@ -940,8 +952,10 @@ func TestGetDriverCapabilities(t *testing.T) {
 		t.Run(tc.description, func(t *testing.T) {
 			var capabilities string
 
-			c := HookConfig{
-				SupportedDriverCapabilities: tc.supportedCapabilities,
+			c := hookConfig{
+				Config: &config.Config{
+					SupportedDriverCapabilities: tc.supportedCapabilities,
+				},
 			}
 
 			image, _ := image.New(

cmd/nvidia-container-runtime-hook/hook_config.go

@@ -17,16 +17,10 @@ const (
 	driverPath = "/run/nvidia/driver"
 )
 
-// HookConfig : options for the nvidia-container-runtime-hook.
-type HookConfig config.Config
-
-func getDefaultHookConfig() (HookConfig, error) {
-	defaultCfg, err := config.GetDefault()
-	if err != nil {
-		return HookConfig{}, err
-	}
-
-	return *(*HookConfig)(defaultCfg), nil
+// hookConfig wraps the toolkit config.
+// This allows for functions to be defined on the local type.
+type hookConfig struct {
+	*config.Config
 }
 
 // loadConfig loads the required paths for the hook config.
@@ -56,12 +50,12 @@ func loadConfig() (*config.Config, error) {
 	return config.GetDefault()
 }
 
-func getHookConfig() (*HookConfig, error) {
+func getHookConfig() (*hookConfig, error) {
 	cfg, err := loadConfig()
 	if err != nil {
 		return nil, fmt.Errorf("failed to load config: %v", err)
 	}
-	config := (*HookConfig)(cfg)
+	config := &hookConfig{cfg}
 
 	allSupportedDriverCapabilities := image.SupportedDriverCapabilities
 	if config.SupportedDriverCapabilities == "all" {
@@ -79,7 +73,7 @@ func getHookConfig() (*HookConfig, error) {
 
 // getConfigOption returns the toml config option associated with the
 // specified struct field.
-func (c HookConfig) getConfigOption(fieldName string) string {
+func (c hookConfig) getConfigOption(fieldName string) string {
 	t := reflect.TypeOf(c)
 	f, ok := t.FieldByName(fieldName)
 	if !ok {
@@ -93,7 +87,7 @@ func (c HookConfig) getConfigOption(fieldName string) string {
 }
 
 // getSwarmResourceEnvvars returns the swarm resource envvars for the config.
-func (c *HookConfig) getSwarmResourceEnvvars() []string {
+func (c *hookConfig) getSwarmResourceEnvvars() []string {
 	if c.SwarmResource == "" {
 		return nil
 	}

cmd/nvidia-container-runtime-hook/hook_config_test.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/config/image"
 )
 
@@ -89,10 +90,10 @@ func TestGetHookConfig(t *testing.T) {
 				}
 			}
 
-			var config HookConfig
+			var cfg hookConfig
 			getHookConfig := func() {
 				c, _ := getHookConfig()
-				config = *c
+				cfg = *c
 			}
 
 			if tc.expectedPanic {
@@ -102,7 +103,7 @@ func TestGetHookConfig(t *testing.T) {
 
 			getHookConfig()
 
-			require.EqualValues(t, tc.expectedDriverCapabilities, config.SupportedDriverCapabilities)
+			require.EqualValues(t, tc.expectedDriverCapabilities, cfg.SupportedDriverCapabilities)
 		})
 	}
 }
@@ -144,8 +145,10 @@ func TestGetSwarmResourceEnvvars(t *testing.T) {
 
 	for i, tc := range testCases {
 		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
-			c := &HookConfig{
-				SwarmResource: tc.value,
+			c := &hookConfig{
+				Config: &config.Config{
+					SwarmResource: tc.value,
+				},
 			}
 
 			envvars := c.getSwarmResourceEnvvars()

cmd/nvidia-container-runtime-hook/main.go

@@ -75,7 +75,7 @@ func doPrestart() {
 	}
 	cli := hook.NVIDIAContainerCLIConfig
 
-	container := getContainerConfig(*hook)
+	container := hook.getContainerConfig()
 	nvidia := container.Nvidia
 	if nvidia == nil {
 		// Not a GPU container, nothing to do.

internal/config/cli.go

@@ -17,6 +17,7 @@
 package config
 
 import (
+	"fmt"
 	"os"
 	"strings"
 )
@@ -34,29 +35,62 @@ type ContainerCLIConfig struct {
 	NoPivot   bool   `toml:"no-pivot,omitempty"`
 	NoCgroups bool   `toml:"no-cgroups"`
 	User      string `toml:"user"`
-	Ldconfig  string `toml:"ldconfig"`
+	// Ldconfig represents the path to the ldconfig binary to be used to update
+	// the ldcache in a container as it is being created.
+	// If this path starts with a '@' the path is relative to the host and if
+	// not it is treated as a container path.
+	//
+	// Note that the use of container paths are disabled by default and if this
+	// is required, the features.allow-ldconfig-from-container feature gate must
+	// be enabled explicitly.
+	Ldconfig ldconfigPath `toml:"ldconfig"`
 }
 
 // NormalizeLDConfigPath returns the resolved path of the configured LDConfig binary.
 // This is only done for host LDConfigs and is required to handle systems where
 // /sbin/ldconfig is a wrapper around /sbin/ldconfig.real.
 func (c *ContainerCLIConfig) NormalizeLDConfigPath() string {
-	return NormalizeLDConfigPath(c.Ldconfig)
+	return string(c.Ldconfig.normalize())
+}
+
+// An ldconfigPath is used to represent the path to ldconfig.
+type ldconfigPath string
+
+func (p ldconfigPath) assertValid(allowContainerRelativePath bool) error {
+	if p.isHostRelative() {
+		return nil
+	}
+	if allowContainerRelativePath {
+		return nil
+	}
+	return fmt.Errorf("nvidia-container-cli.ldconfig value %q is not host-relative (does not start with a '@')", p)
+}
+
+func (p ldconfigPath) isHostRelative() bool {
+	return strings.HasPrefix(string(p), "@")
+}
+
+// normalize returns the resolved path of the configured LDConfig binary.
+// This is only done for host LDConfigs and is required to handle systems where
+// /sbin/ldconfig is a wrapper around /sbin/ldconfig.real.
+func (p ldconfigPath) normalize() ldconfigPath {
+	if !p.isHostRelative() {
+		return p
+	}
+
+	path := string(p)
+	trimmedPath := strings.TrimSuffix(strings.TrimPrefix(path, "@"), ".real")
+	// If the .real path exists, we return that.
+	if _, err := os.Stat(trimmedPath + ".real"); err == nil {
+		return ldconfigPath("@" + trimmedPath + ".real")
+	}
+	// If the .real path does not exists (or cannot be read) we return the non-.real path.
+	return ldconfigPath("@" + trimmedPath)
 }
 
 // NormalizeLDConfigPath returns the resolved path of the configured LDConfig binary.
 // This is only done for host LDConfigs and is required to handle systems where
 // /sbin/ldconfig is a wrapper around /sbin/ldconfig.real.
 func NormalizeLDConfigPath(path string) string {
-	if !strings.HasPrefix(path, "@") {
-		return path
-	}
-
-	trimmedPath := strings.TrimSuffix(strings.TrimPrefix(path, "@"), ".real")
-	// If the .real path exists, we return that.
-	if _, err := os.Stat(trimmedPath + ".real"); err == nil {
-		return "@" + trimmedPath + ".real"
-	}
-	// If the .real path does not exists (or cannot be read) we return the non-.real path.
-	return "@" + trimmedPath
+	return string(ldconfigPath(path).normalize())
 }

internal/config/cli_test.go

@@ -33,7 +33,7 @@ func TestNormalizeLDConfigPath(t *testing.T) {
 
 	testCases := []struct {
 		description string
-		ldconfig    string
+		ldconfig    ldconfigPath
 		expected    string
 	}{
 		{
@@ -51,12 +51,12 @@ func TestNormalizeLDConfigPath(t *testing.T) {
 		},
 		{
 			description: "host .real file exists is returned",
-			ldconfig:    "@" + filepath.Join(testDir, "exists.real"),
+			ldconfig:    ldconfigPath("@" + filepath.Join(testDir, "exists.real")),
 			expected:    "@" + filepath.Join(testDir, "exists.real"),
 		},
 		{
 			description: "host resolves .real file",
-			ldconfig:    "@" + filepath.Join(testDir, "exists"),
+			ldconfig:    ldconfigPath("@" + filepath.Join(testDir, "exists")),
 			expected:    "@" + filepath.Join(testDir, "exists.real"),
 		},
 		{

internal/config/config.go

@@ -18,6 +18,7 @@ package config
 
 import (
 	"bufio"
+	"errors"
 	"os"
 	"path/filepath"
 	"strings"
@@ -51,6 +52,8 @@ var (
 	NVIDIAContainerToolkitExecutable = "nvidia-container-toolkit"
 )
 
+var errInvalidConfig = errors.New("invalid config value")
+
 // Config represents the contents of the config.toml file for the NVIDIA Container Toolkit
 // Note: This is currently duplicated by the HookConfig in cmd/nvidia-container-toolkit/hook_config.go
 type Config struct {
@@ -127,8 +130,20 @@ func GetDefault() (*Config, error) {
 	return &d, nil
 }
 
-func getLdConfigPath() string {
-	return NormalizeLDConfigPath("@/sbin/ldconfig")
+// assertValid checks for a valid config.
+func (c *Config) assertValid() error {
+	err := c.NVIDIAContainerCLIConfig.Ldconfig.assertValid(c.Features.AllowLDConfigFromContainer.IsEnabled())
+	if err != nil {
+		return errors.Join(err, errInvalidConfig)
+	}
+	return nil
+}
+
+// getLdConfigPath allows us to override this function for testing.
+var getLdConfigPath = getLdConfigPathStub
+
+func getLdConfigPathStub() ldconfigPath {
+	return ldconfigPath("@/sbin/ldconfig").normalize()
 }
 
 func getUserGroup() string {

internal/config/config_test.go

@@ -44,23 +44,21 @@ func TestGetConfigWithCustomConfig(t *testing.T) {
 
 func TestGetConfig(t *testing.T) {
 	testCases := []struct {
-		description     string
-		contents        []string
-		expectedError   error
-		inspectLdconfig bool
-		distIdsLike     []string
-		expectedConfig  *Config
+		description    string
+		contents       []string
+		expectedError  error
+		distIdsLike    []string
+		expectedConfig *Config
 	}{
 		{
-			description:     "empty config is default",
-			inspectLdconfig: true,
+			description: "empty config is default",
 			expectedConfig: &Config{
 				AcceptEnvvarUnprivileged:    true,
 				SupportedDriverCapabilities: "compat32,compute,display,graphics,ngx,utility,video",
 				NVIDIAContainerCLIConfig: ContainerCLIConfig{
 					Root:      "",
 					LoadKmods: true,
-					Ldconfig:  "WAS_CHECKED",
+					Ldconfig:  "@/test/ld/config/path",
 				},
 				NVIDIAContainerRuntimeConfig: RuntimeConfig{
 					DebugFilePath: "/dev/null",
@@ -93,7 +91,7 @@ func TestGetConfig(t *testing.T) {
 				"supported-driver-capabilities = \"compute,utility\"",
 				"nvidia-container-cli.root = \"/bar/baz\"",
 				"nvidia-container-cli.load-kmods = false",
-				"nvidia-container-cli.ldconfig = \"/foo/bar/ldconfig\"",
+				"nvidia-container-cli.ldconfig = \"@/foo/bar/ldconfig\"",
 				"nvidia-container-cli.user = \"foo:bar\"",
 				"nvidia-container-runtime.debug = \"/foo/bar\"",
 				"nvidia-container-runtime.discover-mode = \"not-legacy\"",
@@ -113,7 +111,7 @@ func TestGetConfig(t *testing.T) {
 				NVIDIAContainerCLIConfig: ContainerCLIConfig{
 					Root:      "/bar/baz",
 					LoadKmods: false,
-					Ldconfig:  "/foo/bar/ldconfig",
+					Ldconfig:  "@/foo/bar/ldconfig",
 					User:      "foo:bar",
 				},
 				NVIDIAContainerRuntimeConfig: RuntimeConfig{
@@ -146,6 +144,53 @@ func TestGetConfig(t *testing.T) {
 				},
 			},
 		},
+		{
+			description: "feature allows ldconfig to be overridden",
+			contents: []string{
+				"[nvidia-container-cli]",
+				"ldconfig = \"/foo/bar/ldconfig\"",
+				"[features]",
+				"allow-ldconfig-from-container = true",
+			},
+			expectedConfig: &Config{
+				AcceptEnvvarUnprivileged:    true,
+				SupportedDriverCapabilities: "compat32,compute,display,graphics,ngx,utility,video",
+				NVIDIAContainerCLIConfig: ContainerCLIConfig{
+					Ldconfig:  "/foo/bar/ldconfig",
+					LoadKmods: true,
+				},
+				NVIDIAContainerRuntimeConfig: RuntimeConfig{
+					DebugFilePath: "/dev/null",
+					LogLevel:      "info",
+					Runtimes:      []string{"docker-runc", "runc", "crun"},
+					Mode:          "auto",
+					Modes: modesConfig{
+						CSV: csvModeConfig{
+							MountSpecPath: "/etc/nvidia-container-runtime/host-files-for-container.d",
+						},
+						CDI: cdiModeConfig{
+							DefaultKind: "nvidia.com/gpu",
+							AnnotationPrefixes: []string{
+								"cdi.k8s.io/",
+							},
+							SpecDirs: []string{
+								"/etc/cdi",
+								"/var/run/cdi",
+							},
+						},
+					},
+				},
+				NVIDIAContainerRuntimeHookConfig: RuntimeHookConfig{
+					Path: "nvidia-container-runtime-hook",
+				},
+				NVIDIACTKConfig: CTKConfig{
+					Path: "nvidia-ctk",
+				},
+				Features: features{
+					AllowLDConfigFromContainer: ptr(feature(true)),
+				},
+			},
+		},
 		{
 			description: "config options set in section",
 			contents: []string{
@@ -154,7 +199,7 @@ func TestGetConfig(t *testing.T) {
 				"[nvidia-container-cli]",
 				"root = \"/bar/baz\"",
 				"load-kmods = false",
-				"ldconfig = \"/foo/bar/ldconfig\"",
+				"ldconfig = \"@/foo/bar/ldconfig\"",
 				"user = \"foo:bar\"",
 				"[nvidia-container-runtime]",
 				"debug = \"/foo/bar\"",
@@ -179,7 +224,7 @@ func TestGetConfig(t *testing.T) {
 				NVIDIAContainerCLIConfig: ContainerCLIConfig{
 					Root:      "/bar/baz",
 					LoadKmods: false,
-					Ldconfig:  "/foo/bar/ldconfig",
+					Ldconfig:  "@/foo/bar/ldconfig",
 					User:      "foo:bar",
 				},
 				NVIDIAContainerRuntimeConfig: RuntimeConfig{
@@ -213,16 +258,15 @@ func TestGetConfig(t *testing.T) {
 			},
 		},
 		{
-			description:     "suse config",
-			distIdsLike:     []string{"suse", "opensuse"},
-			inspectLdconfig: true,
+			description: "suse config",
+			distIdsLike: []string{"suse", "opensuse"},
 			expectedConfig: &Config{
 				AcceptEnvvarUnprivileged:    true,
 				SupportedDriverCapabilities: "compat32,compute,display,graphics,ngx,utility,video",
 				NVIDIAContainerCLIConfig: ContainerCLIConfig{
 					Root:      "",
 					LoadKmods: true,
-					Ldconfig:  "WAS_CHECKED",
+					Ldconfig:  "@/test/ld/config/path",
 					User:      "root:video",
 				},
 				NVIDIAContainerRuntimeConfig: RuntimeConfig{
@@ -250,9 +294,8 @@ func TestGetConfig(t *testing.T) {
 			},
 		},
 		{
-			description:     "suse config overrides user",
-			distIdsLike:     []string{"suse", "opensuse"},
-			inspectLdconfig: true,
+			description: "suse config overrides user",
+			distIdsLike: []string{"suse", "opensuse"},
 			contents: []string{
 				"nvidia-container-cli.user = \"foo:bar\"",
 			},
@@ -262,7 +305,7 @@ func TestGetConfig(t *testing.T) {
 				NVIDIAContainerCLIConfig: ContainerCLIConfig{
 					Root:      "",
 					LoadKmods: true,
-					Ldconfig:  "WAS_CHECKED",
+					Ldconfig:  "@/test/ld/config/path",
 					User:      "foo:bar",
 				},
 				NVIDIAContainerRuntimeConfig: RuntimeConfig{
@@ -293,6 +336,7 @@ func TestGetConfig(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.description, func(t *testing.T) {
+			defer setGetLdConfigPathForTest()()
 			defer setGetDistIDLikeForTest(tc.distIdsLike)()
 			reader := strings.NewReader(strings.Join(tc.contents, "\n"))
 
@@ -305,21 +349,63 @@ func TestGetConfig(t *testing.T) {
 			cfg, err := tomlCfg.Config()
 			require.NoError(t, err)
 
-			// We first handle the ldconfig path since this is currently system-dependent.
-			if tc.inspectLdconfig {
-				ldconfig := cfg.NVIDIAContainerCLIConfig.Ldconfig
-				require.True(t, strings.HasPrefix(ldconfig, "@/sbin/ldconfig"))
-				remaining := strings.TrimPrefix(ldconfig, "@/sbin/ldconfig")
-				require.True(t, remaining == ".real" || remaining == "")
-
-				cfg.NVIDIAContainerCLIConfig.Ldconfig = "WAS_CHECKED"
-			}
-
 			require.EqualValues(t, tc.expectedConfig, cfg)
 		})
 	}
 }
 
+func TestAssertValid(t *testing.T) {
+	defer setGetLdConfigPathForTest()()
+
+	testCases := []struct {
+		description   string
+		config        *Config
+		expectedError error
+	}{
+		{
+			description: "default is valid",
+			config: func() *Config {
+				config, _ := GetDefault()
+				return config
+			}(),
+		},
+		{
+			description: "alternative host ldconfig path is valid",
+			config: &Config{
+				NVIDIAContainerCLIConfig: ContainerCLIConfig{
+					Ldconfig: "@/some/host/path",
+				},
+			},
+		},
+		{
+			description: "non-host path is invalid",
+			config: &Config{
+				NVIDIAContainerCLIConfig: ContainerCLIConfig{
+					Ldconfig: "/non/host/path",
+				},
+			},
+			expectedError: errInvalidConfig,
+		},
+		{
+			description: "feature flag allows non-host path",
+			config: &Config{
+				NVIDIAContainerCLIConfig: ContainerCLIConfig{
+					Ldconfig: "/non/host/path",
+				},
+				Features: features{
+					AllowLDConfigFromContainer: ptr(feature(true)),
+				},
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			require.ErrorIs(t, tc.config.assertValid(), tc.expectedError)
+		})
+	}
+}
+
 // setGetDistIDsLikeForTest overrides the distribution IDs that would normally be read from the /etc/os-release file.
 func setGetDistIDLikeForTest(ids []string) func() {
 	if ids == nil {
@@ -335,3 +421,18 @@ func setGetDistIDLikeForTest(ids []string) func() {
 		getDistIDLike = original
 	}
 }
+
+// prt returns a reference to whatever type is passed into it
+func ptr[T any](x T) *T {
+	return &x
+}
+
+func setGetLdConfigPathForTest() func() {
+	previous := getLdConfigPath
+	getLdConfigPath = func() ldconfigPath {
+		return "@/test/ld/config/path"
+	}
+	return func() {
+		getLdConfigPath = previous
+	}
+}

internal/config/features.go

@@ -21,14 +21,15 @@ type features struct {
 	// DisableImexChannelCreation ensures that the implicit creation of
 	// requested IMEX channels is skipped when invoking the nvidia-container-cli.
 	DisableImexChannelCreation *feature `toml:"disable-imex-channel-creation,omitempty"`
+	// AllowLDConfigFromContainer allows non-host ldconfig paths to be used.
+	// If this feature flag is not set to 'true' only host-rooted config paths
+	// (i.e. paths starting with an '@' are considered valid)
+	AllowLDConfigFromContainer *feature `toml:"allow-ldconfig-from-container,omitempty"`
 }
 
-//nolint:unused
 type feature bool
 
 // IsEnabled checks whether a feature is explicitly enabled.
-//
-//nolint:unused
 func (f *feature) IsEnabled() bool {
 	if f != nil {
 		return bool(*f)

internal/config/hook.go

@@ -24,13 +24,3 @@ type RuntimeHookConfig struct {
 	// SkipModeDetection disables the mode check for the runtime hook.
 	SkipModeDetection bool `toml:"skip-mode-detection"`
 }
-
-// GetDefaultRuntimeHookConfig defines the default values for the config
-func GetDefaultRuntimeHookConfig() (*RuntimeHookConfig, error) {
-	cfg, err := GetDefault()
-	if err != nil {
-		return nil, err
-	}
-
-	return &cfg.NVIDIAContainerRuntimeHookConfig, nil
-}

internal/config/runtime.go

@@ -45,13 +45,3 @@ type cdiModeConfig struct {
 type csvModeConfig struct {
 	MountSpecPath string `toml:"mount-spec-path"`
 }
-
-// GetDefaultRuntimeConfig defines the default values for the config
-func GetDefaultRuntimeConfig() (*RuntimeConfig, error) {
-	cfg, err := GetDefault()
-	if err != nil {
-		return nil, err
-	}
-
-	return &cfg.NVIDIAContainerRuntimeConfig, nil
-}

internal/config/toml.go

@@ -108,6 +108,19 @@ func loadConfigTomlFrom(reader io.Reader) (*Toml, error) {
 
 // Config returns the typed config associated with the toml tree.
 func (t *Toml) Config() (*Config, error) {
+	cfg, err := t.configNoOverrides()
+	if err != nil {
+		return nil, err
+	}
+	if err := cfg.assertValid(); err != nil {
+		return nil, err
+	}
+	return cfg, nil
+}
+
+// configNoOverrides returns the typed config associated with the toml tree.
+// This config does not include feature-specific overrides.
+func (t *Toml) configNoOverrides() (*Config, error) {
 	cfg, err := GetDefault()
 	if err != nil {
 		return nil, err

internal/config/toml_test.go

@@ -198,9 +198,12 @@ func TestTomlContents(t *testing.T) {
 }
 
 func TestConfigFromToml(t *testing.T) {
+	defer setGetLdConfigPathForTest()()
+
 	testCases := []struct {
 		description    string
 		contents       map[string]interface{}
+		expectedError  error
 		expectedConfig *Config
 	}{
 		{
@@ -226,13 +229,39 @@ func TestConfigFromToml(t *testing.T) {
 				return c
 			}(),
 		},
+		{
+			description: "invalid ldconfig value raises error",
+			contents: map[string]interface{}{
+				"nvidia-container-cli": map[string]interface{}{
+					"ldconfig": "/some/ldconfig/path",
+				},
+			},
+			expectedError: errInvalidConfig,
+		},
+		{
+			description: "feature allows ldconfig override",
+			contents: map[string]interface{}{
+				"nvidia-container-cli": map[string]interface{}{
+					"ldconfig": "/some/ldconfig/path",
+				},
+				"features": map[string]interface{}{
+					"allow-ldconfig-from-container": true,
+				},
+			},
+			expectedConfig: func() *Config {
+				c, _ := GetDefault()
+				c.NVIDIAContainerCLIConfig.Ldconfig = "/some/ldconfig/path"
+				c.Features.AllowLDConfigFromContainer = ptr(feature(true))
+				return c
+			}(),
+		},
 	}
 
 	for _, tc := range testCases {
 		t.Run(tc.description, func(t *testing.T) {
 			tomlCfg := fromMap(tc.contents)
 			config, err := tomlCfg.Config()
-			require.NoError(t, err)
+			require.ErrorIs(t, err, tc.expectedError)
 			require.EqualValues(t, tc.expectedConfig, config)
 		})
 	}

tools/container/toolkit/toolkit_test.go

@@ -161,7 +161,7 @@ kind: example.com/class
 			// Ensure that the config file has the required contents.
 			// TODO: Add checks for additional config options.
 			require.Equal(t, "/host/driver/root", cfg.NVIDIAContainerCLIConfig.Root)
-			require.Equal(t, "@/host/driver/root/sbin/ldconfig", cfg.NVIDIAContainerCLIConfig.Ldconfig)
+			require.Equal(t, "@/host/driver/root/sbin/ldconfig", string(cfg.NVIDIAContainerCLIConfig.Ldconfig))
 			require.EqualValues(t, filepath.Join(toolkitRoot, "nvidia-container-cli"), cfg.NVIDIAContainerCLIConfig.Path)
 			require.EqualValues(t, filepath.Join(toolkitRoot, "nvidia-ctk"), cfg.NVIDIACTKConfig.Path)