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moby--moby/daemon/create.go
Brian Goff 93ac040bf0 Lock down docker root dir perms.
Do not use 0701 perms.
0701 dir perms allows anyone to traverse the docker dir.
It happens to allow any user to execute, as an example, suid binaries
from image rootfs dirs because it allows traversal AND critically
container users need to be able to do execute things.

0701 on lower directories also happens to allow any user to modify
     things in, for instance, the overlay upper dir which neccessarily
     has 0755 permissions.

This changes to use 0710 which allows users in the group to traverse.
In userns mode the UID owner is (real) root and the GID is the remapped
root's GID.

This prevents anyone but the remapped root to traverse our directories
(which is required for userns with runc).

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit ef7237442147441a7cadcda0600be1186d81ac73)
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
2021-08-19 20:40:15 +00:00

362 lines
12 KiB
Go

package daemon // import "github.com/docker/docker/daemon"
import (
"fmt"
"net"
"runtime"
"strings"
"time"
"github.com/containerd/containerd/platforms"
"github.com/docker/docker/api/types"
containertypes "github.com/docker/docker/api/types/container"
networktypes "github.com/docker/docker/api/types/network"
"github.com/docker/docker/container"
"github.com/docker/docker/daemon/images"
"github.com/docker/docker/errdefs"
"github.com/docker/docker/image"
"github.com/docker/docker/pkg/idtools"
"github.com/docker/docker/pkg/system"
"github.com/docker/docker/runconfig"
v1 "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/opencontainers/selinux/go-selinux"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
type createOpts struct {
params types.ContainerCreateConfig
managed bool
ignoreImagesArgsEscaped bool
}
// CreateManagedContainer creates a container that is managed by a Service
func (daemon *Daemon) CreateManagedContainer(params types.ContainerCreateConfig) (containertypes.ContainerCreateCreatedBody, error) {
return daemon.containerCreate(createOpts{
params: params,
managed: true,
ignoreImagesArgsEscaped: false})
}
// ContainerCreate creates a regular container
func (daemon *Daemon) ContainerCreate(params types.ContainerCreateConfig) (containertypes.ContainerCreateCreatedBody, error) {
return daemon.containerCreate(createOpts{
params: params,
managed: false,
ignoreImagesArgsEscaped: false})
}
// ContainerCreateIgnoreImagesArgsEscaped creates a regular container. This is called from the builder RUN case
// and ensures that we do not take the images ArgsEscaped
func (daemon *Daemon) ContainerCreateIgnoreImagesArgsEscaped(params types.ContainerCreateConfig) (containertypes.ContainerCreateCreatedBody, error) {
return daemon.containerCreate(createOpts{
params: params,
managed: false,
ignoreImagesArgsEscaped: true})
}
func (daemon *Daemon) containerCreate(opts createOpts) (containertypes.ContainerCreateCreatedBody, error) {
start := time.Now()
if opts.params.Config == nil {
return containertypes.ContainerCreateCreatedBody{}, errdefs.InvalidParameter(errors.New("Config cannot be empty in order to create a container"))
}
os := runtime.GOOS
var img *image.Image
if opts.params.Config.Image != "" {
var err error
img, err = daemon.imageService.GetImage(opts.params.Config.Image, opts.params.Platform)
if err == nil {
os = img.OS
}
} else {
// This mean scratch. On Windows, we can safely assume that this is a linux
// container. On other platforms, it's the host OS (which it already is)
if isWindows && system.LCOWSupported() {
os = "linux"
}
}
warnings, err := daemon.verifyContainerSettings(os, opts.params.HostConfig, opts.params.Config, false)
if err != nil {
return containertypes.ContainerCreateCreatedBody{Warnings: warnings}, errdefs.InvalidParameter(err)
}
if img != nil && opts.params.Platform == nil {
p := platforms.DefaultSpec()
imgPlat := v1.Platform{
OS: img.OS,
Architecture: img.Architecture,
Variant: img.Variant,
}
if !images.OnlyPlatformWithFallback(p).Match(imgPlat) {
warnings = append(warnings, fmt.Sprintf("The requested image's platform (%s) does not match the detected host platform (%s) and no specific platform was requested", platforms.Format(imgPlat), platforms.Format(p)))
}
}
err = verifyNetworkingConfig(opts.params.NetworkingConfig)
if err != nil {
return containertypes.ContainerCreateCreatedBody{Warnings: warnings}, errdefs.InvalidParameter(err)
}
if opts.params.HostConfig == nil {
opts.params.HostConfig = &containertypes.HostConfig{}
}
err = daemon.adaptContainerSettings(opts.params.HostConfig, opts.params.AdjustCPUShares)
if err != nil {
return containertypes.ContainerCreateCreatedBody{Warnings: warnings}, errdefs.InvalidParameter(err)
}
ctr, err := daemon.create(opts)
if err != nil {
return containertypes.ContainerCreateCreatedBody{Warnings: warnings}, err
}
containerActions.WithValues("create").UpdateSince(start)
if warnings == nil {
warnings = make([]string, 0) // Create an empty slice to avoid https://github.com/moby/moby/issues/38222
}
return containertypes.ContainerCreateCreatedBody{ID: ctr.ID, Warnings: warnings}, nil
}
// Create creates a new container from the given configuration with a given name.
func (daemon *Daemon) create(opts createOpts) (retC *container.Container, retErr error) {
var (
ctr *container.Container
img *image.Image
imgID image.ID
err error
)
os := runtime.GOOS
if opts.params.Config.Image != "" {
img, err = daemon.imageService.GetImage(opts.params.Config.Image, opts.params.Platform)
if err != nil {
return nil, err
}
if img.OS != "" {
os = img.OS
} else {
// default to the host OS except on Windows with LCOW
if isWindows && system.LCOWSupported() {
os = "linux"
}
}
imgID = img.ID()
if isWindows && img.OS == "linux" && !system.LCOWSupported() {
return nil, errors.New("operating system on which parent image was created is not Windows")
}
} else {
if isWindows {
os = "linux" // 'scratch' case.
}
}
// On WCOW, if are not being invoked by the builder to create this container (where
// ignoreImagesArgEscaped will be true) - if the image already has its arguments escaped,
// ensure that this is replicated across to the created container to avoid double-escaping
// of the arguments/command line when the runtime attempts to run the container.
if os == "windows" && !opts.ignoreImagesArgsEscaped && img != nil && img.RunConfig().ArgsEscaped {
opts.params.Config.ArgsEscaped = true
}
if err := daemon.mergeAndVerifyConfig(opts.params.Config, img); err != nil {
return nil, errdefs.InvalidParameter(err)
}
if err := daemon.mergeAndVerifyLogConfig(&opts.params.HostConfig.LogConfig); err != nil {
return nil, errdefs.InvalidParameter(err)
}
if ctr, err = daemon.newContainer(opts.params.Name, os, opts.params.Config, opts.params.HostConfig, imgID, opts.managed); err != nil {
return nil, err
}
defer func() {
if retErr != nil {
if err := daemon.cleanupContainer(ctr, true, true); err != nil {
logrus.Errorf("failed to cleanup container on create error: %v", err)
}
}
}()
if err := daemon.setSecurityOptions(ctr, opts.params.HostConfig); err != nil {
return nil, err
}
ctr.HostConfig.StorageOpt = opts.params.HostConfig.StorageOpt
// Fixes: https://github.com/moby/moby/issues/34074 and
// https://github.com/docker/for-win/issues/999.
// Merge the daemon's storage options if they aren't already present. We only
// do this on Windows as there's no effective sandbox size limit other than
// physical on Linux.
if isWindows {
if ctr.HostConfig.StorageOpt == nil {
ctr.HostConfig.StorageOpt = make(map[string]string)
}
for _, v := range daemon.configStore.GraphOptions {
opt := strings.SplitN(v, "=", 2)
if _, ok := ctr.HostConfig.StorageOpt[opt[0]]; !ok {
ctr.HostConfig.StorageOpt[opt[0]] = opt[1]
}
}
}
// Set RWLayer for container after mount labels have been set
rwLayer, err := daemon.imageService.CreateLayer(ctr, setupInitLayer(daemon.idMapping))
if err != nil {
return nil, errdefs.System(err)
}
ctr.RWLayer = rwLayer
current := idtools.CurrentIdentity()
if err := idtools.MkdirAndChown(ctr.Root, 0710, idtools.Identity{UID: current.UID, GID: daemon.IdentityMapping().RootPair().GID}); err != nil {
return nil, err
}
if err := idtools.MkdirAndChown(ctr.CheckpointDir(), 0700, current); err != nil {
return nil, err
}
if err := daemon.setHostConfig(ctr, opts.params.HostConfig); err != nil {
return nil, err
}
if err := daemon.createContainerOSSpecificSettings(ctr, opts.params.Config, opts.params.HostConfig); err != nil {
return nil, err
}
var endpointsConfigs map[string]*networktypes.EndpointSettings
if opts.params.NetworkingConfig != nil {
endpointsConfigs = opts.params.NetworkingConfig.EndpointsConfig
}
// Make sure NetworkMode has an acceptable value. We do this to ensure
// backwards API compatibility.
runconfig.SetDefaultNetModeIfBlank(ctr.HostConfig)
daemon.updateContainerNetworkSettings(ctr, endpointsConfigs)
if err := daemon.Register(ctr); err != nil {
return nil, err
}
stateCtr.set(ctr.ID, "stopped")
daemon.LogContainerEvent(ctr, "create")
return ctr, nil
}
func toHostConfigSelinuxLabels(labels []string) []string {
for i, l := range labels {
labels[i] = "label=" + l
}
return labels
}
func (daemon *Daemon) generateSecurityOpt(hostConfig *containertypes.HostConfig) ([]string, error) {
for _, opt := range hostConfig.SecurityOpt {
con := strings.Split(opt, "=")
if con[0] == "label" {
// Caller overrode SecurityOpts
return nil, nil
}
}
ipcMode := hostConfig.IpcMode
pidMode := hostConfig.PidMode
privileged := hostConfig.Privileged
if ipcMode.IsHost() || pidMode.IsHost() || privileged {
return toHostConfigSelinuxLabels(selinux.DisableSecOpt()), nil
}
var ipcLabel []string
var pidLabel []string
ipcContainer := ipcMode.Container()
pidContainer := pidMode.Container()
if ipcContainer != "" {
c, err := daemon.GetContainer(ipcContainer)
if err != nil {
return nil, err
}
ipcLabel, err = selinux.DupSecOpt(c.ProcessLabel)
if err != nil {
return nil, err
}
if pidContainer == "" {
return toHostConfigSelinuxLabels(ipcLabel), err
}
}
if pidContainer != "" {
c, err := daemon.GetContainer(pidContainer)
if err != nil {
return nil, err
}
pidLabel, err = selinux.DupSecOpt(c.ProcessLabel)
if err != nil {
return nil, err
}
if ipcContainer == "" {
return toHostConfigSelinuxLabels(pidLabel), err
}
}
if pidLabel != nil && ipcLabel != nil {
for i := 0; i < len(pidLabel); i++ {
if pidLabel[i] != ipcLabel[i] {
return nil, fmt.Errorf("--ipc and --pid containers SELinux labels aren't the same")
}
}
return toHostConfigSelinuxLabels(pidLabel), nil
}
return nil, nil
}
func (daemon *Daemon) mergeAndVerifyConfig(config *containertypes.Config, img *image.Image) error {
if img != nil && img.Config != nil {
if err := merge(config, img.Config); err != nil {
return err
}
}
// Reset the Entrypoint if it is [""]
if len(config.Entrypoint) == 1 && config.Entrypoint[0] == "" {
config.Entrypoint = nil
}
if len(config.Entrypoint) == 0 && len(config.Cmd) == 0 {
return fmt.Errorf("No command specified")
}
return nil
}
// Checks if the client set configurations for more than one network while creating a container
// Also checks if the IPAMConfig is valid
func verifyNetworkingConfig(nwConfig *networktypes.NetworkingConfig) error {
if nwConfig == nil || len(nwConfig.EndpointsConfig) == 0 {
return nil
}
if len(nwConfig.EndpointsConfig) > 1 {
l := make([]string, 0, len(nwConfig.EndpointsConfig))
for k := range nwConfig.EndpointsConfig {
l = append(l, k)
}
return errors.Errorf("Container cannot be connected to network endpoints: %s", strings.Join(l, ", "))
}
for k, v := range nwConfig.EndpointsConfig {
if v == nil {
return errdefs.InvalidParameter(errors.Errorf("no EndpointSettings for %s", k))
}
if v.IPAMConfig != nil {
if v.IPAMConfig.IPv4Address != "" && net.ParseIP(v.IPAMConfig.IPv4Address).To4() == nil {
return errors.Errorf("invalid IPv4 address: %s", v.IPAMConfig.IPv4Address)
}
if v.IPAMConfig.IPv6Address != "" {
n := net.ParseIP(v.IPAMConfig.IPv6Address)
// if the address is an invalid network address (ParseIP == nil) or if it is
// an IPv4 address (To4() != nil), then it is an invalid IPv6 address
if n == nil || n.To4() != nil {
return errors.Errorf("invalid IPv6 address: %s", v.IPAMConfig.IPv6Address)
}
}
}
}
return nil
}