Vendor in latest opencontainers/selinux

This will now verify labels passed in by the user.
Will also prevent users from accidently relabeling their homedir.

podman run -ti -v ~/home/user:Z fedora sh

Is not a good idea.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
This commit is contained in:
Daniel J Walsh
2019-01-18 15:01:53 -05:00
parent 37002ad549
commit 8cf929c095
7 changed files with 111 additions and 30 deletions

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@ -173,7 +173,11 @@ func parseSecurityOpt(config *cc.CreateConfig, securityOpts []string) error {
if err != nil { if err != nil {
return errors.Wrapf(err, "container %q not found", config.PidMode.Container()) return errors.Wrapf(err, "container %q not found", config.PidMode.Container())
} }
labelOpts = append(labelOpts, label.DupSecOpt(ctr.ProcessLabel())...) secopts, err := label.DupSecOpt(ctr.ProcessLabel())
if err != nil {
return errors.Wrapf(err, "failed to duplicate label %q ", ctr.ProcessLabel())
}
labelOpts = append(labelOpts, secopts...)
} }
if config.IpcMode.IsHost() { if config.IpcMode.IsHost() {
@ -183,7 +187,11 @@ func parseSecurityOpt(config *cc.CreateConfig, securityOpts []string) error {
if err != nil { if err != nil {
return errors.Wrapf(err, "container %q not found", config.IpcMode.Container()) return errors.Wrapf(err, "container %q not found", config.IpcMode.Container())
} }
labelOpts = append(labelOpts, label.DupSecOpt(ctr.ProcessLabel())...) secopts, err := label.DupSecOpt(ctr.ProcessLabel())
if err != nil {
return errors.Wrapf(err, "failed to duplicate label %q ", ctr.ProcessLabel())
}
labelOpts = append(labelOpts, secopts...)
} }
for _, opt := range securityOpts { for _, opt := range securityOpts {

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@ -356,18 +356,25 @@ func (r *OCIRuntime) createOCIContainer(ctr *Container, cgroupParent string, res
// Set the label of the conmon process to be level :s0 // Set the label of the conmon process to be level :s0
// This will allow the container processes to talk to fifo-files // This will allow the container processes to talk to fifo-files
// passed into the container by conmon // passed into the container by conmon
var plabel string var (
plabel string
con selinux.Context
)
plabel, err = selinux.CurrentLabel() plabel, err = selinux.CurrentLabel()
if err != nil { if err != nil {
childPipe.Close() childPipe.Close()
return errors.Wrapf(err, "Failed to get current SELinux label") return errors.Wrapf(err, "Failed to get current SELinux label")
} }
c := selinux.NewContext(plabel) con, err = selinux.NewContext(plabel)
if err != nil {
return errors.Wrapf(err, "Failed to get new context from SELinux label")
}
runtime.LockOSThread() runtime.LockOSThread()
if c["level"] != "s0" && c["level"] != "" { if con["level"] != "s0" && con["level"] != "" {
c["level"] = "s0" con["level"] = "s0"
if err = label.SetProcessLabel(c.Get()); err != nil { if err = label.SetProcessLabel(con.Get()); err != nil {
runtime.UnlockOSThread() runtime.UnlockOSThread()
return err return err
} }

View File

@ -54,7 +54,7 @@ github.com/opencontainers/image-spec v1.0.0
github.com/opencontainers/runc v1.0.0-rc6 github.com/opencontainers/runc v1.0.0-rc6
github.com/opencontainers/runtime-spec 1722abf79c2f8f2675f47367f827c6491472cf27 github.com/opencontainers/runtime-spec 1722abf79c2f8f2675f47367f827c6491472cf27
github.com/opencontainers/runtime-tools v0.8.0 github.com/opencontainers/runtime-tools v0.8.0
github.com/opencontainers/selinux v1.0.0 github.com/opencontainers/selinux v1.1
github.com/ostreedev/ostree-go d0388bd827cfac6fa8eec760246eb8375674b2a0 github.com/ostreedev/ostree-go d0388bd827cfac6fa8eec760246eb8375674b2a0
github.com/pkg/errors v0.8.1 github.com/pkg/errors v0.8.1
github.com/pmezard/go-difflib v1.0.0 github.com/pmezard/go-difflib v1.0.0

View File

@ -75,8 +75,8 @@ func ReleaseLabel(label string) error {
// DupSecOpt takes a process label and returns security options that // DupSecOpt takes a process label and returns security options that
// can be used to set duplicate labels on future container processes // can be used to set duplicate labels on future container processes
func DupSecOpt(src string) []string { func DupSecOpt(src string) ([]string, error) {
return nil return nil, nil
} }
// DisableSecOpt returns a security opt that can disable labeling // DisableSecOpt returns a security opt that can disable labeling

View File

@ -4,6 +4,8 @@ package label
import ( import (
"fmt" "fmt"
"os"
"os/user"
"strings" "strings"
"github.com/opencontainers/selinux/go-selinux" "github.com/opencontainers/selinux/go-selinux"
@ -35,8 +37,15 @@ func InitLabels(options []string) (plabel string, mlabel string, Err error) {
ReleaseLabel(mountLabel) ReleaseLabel(mountLabel)
} }
}() }()
pcon := selinux.NewContext(processLabel) pcon, err := selinux.NewContext(processLabel)
mcon := selinux.NewContext(mountLabel) if err != nil {
return "", "", err
}
mcon, err := selinux.NewContext(mountLabel)
if err != nil {
return "", "", err
}
for _, opt := range options { for _, opt := range options {
if opt == "disable" { if opt == "disable" {
return "", mountLabel, nil return "", mountLabel, nil
@ -146,13 +155,56 @@ func Relabel(path string, fileLabel string, shared bool) error {
return nil return nil
} }
exclude_paths := map[string]bool{"/": true, "/usr": true, "/etc": true, "/tmp": true, "/home": true, "/run": true, "/var": true, "/root": true} exclude_paths := map[string]bool{
"/": true,
"/bin": true,
"/boot": true,
"/dev": true,
"/etc": true,
"/etc/passwd": true,
"/etc/pki": true,
"/etc/shadow": true,
"/home": true,
"/lib": true,
"/lib64": true,
"/media": true,
"/opt": true,
"/proc": true,
"/root": true,
"/run": true,
"/sbin": true,
"/srv": true,
"/sys": true,
"/tmp": true,
"/usr": true,
"/var": true,
"/var/lib": true,
"/var/log": true,
}
if home := os.Getenv("HOME"); home != "" {
exclude_paths[home] = true
}
if sudoUser := os.Getenv("SUDO_USER"); sudoUser != "" {
if usr, err := user.Lookup(sudoUser); err == nil {
exclude_paths[usr.HomeDir] = true
}
}
if path != "/" {
path = strings.TrimSuffix(path, "/")
}
if exclude_paths[path] { if exclude_paths[path] {
return fmt.Errorf("SELinux relabeling of %s is not allowed", path) return fmt.Errorf("SELinux relabeling of %s is not allowed", path)
} }
if shared { if shared {
c := selinux.NewContext(fileLabel) c, err := selinux.NewContext(fileLabel)
if err != nil {
return err
}
c["level"] = "s0" c["level"] = "s0"
fileLabel = c.Get() fileLabel = c.Get()
} }
@ -195,7 +247,7 @@ func ReleaseLabel(label string) error {
// DupSecOpt takes a process label and returns security options that // DupSecOpt takes a process label and returns security options that
// can be used to set duplicate labels on future container processes // can be used to set duplicate labels on future container processes
func DupSecOpt(src string) []string { func DupSecOpt(src string) ([]string, error) {
return selinux.DupSecOpt(src) return selinux.DupSecOpt(src)
} }

View File

@ -52,6 +52,8 @@ var (
ErrMCSAlreadyExists = errors.New("MCS label already exists") ErrMCSAlreadyExists = errors.New("MCS label already exists")
// ErrEmptyPath is returned when an empty path has been specified. // ErrEmptyPath is returned when an empty path has been specified.
ErrEmptyPath = errors.New("empty path") ErrEmptyPath = errors.New("empty path")
// InvalidLabel is returned when an invalid label is specified.
InvalidLabel = errors.New("Invalid Label")
assignRegex = regexp.MustCompile(`^([^=]+)=(.*)$`) assignRegex = regexp.MustCompile(`^([^=]+)=(.*)$`)
roFileLabel string roFileLabel string
@ -405,11 +407,14 @@ func (c Context) Get() string {
} }
// NewContext creates a new Context struct from the specified label // NewContext creates a new Context struct from the specified label
func NewContext(label string) Context { func NewContext(label string) (Context, error) {
c := make(Context) c := make(Context)
if len(label) != 0 { if len(label) != 0 {
con := strings.SplitN(label, ":", 4) con := strings.SplitN(label, ":", 4)
if len(con) < 3 {
return c, InvalidLabel
}
c["user"] = con[0] c["user"] = con[0]
c["role"] = con[1] c["role"] = con[1]
c["type"] = con[2] c["type"] = con[2]
@ -417,7 +422,7 @@ func NewContext(label string) Context {
c["level"] = con[3] c["level"] = con[3]
} }
} }
return c return c, nil
} }
// ClearLabels clears all reserved labels // ClearLabels clears all reserved labels
@ -630,12 +635,12 @@ func ContainerLabels() (processLabel string, fileLabel string) {
roFileLabel = fileLabel roFileLabel = fileLabel
} }
exit: exit:
scon := NewContext(processLabel) scon, _ := NewContext(processLabel)
if scon["level"] != "" { if scon["level"] != "" {
mcs := uniqMcs(1024) mcs := uniqMcs(1024)
scon["level"] = mcs scon["level"] = mcs
processLabel = scon.Get() processLabel = scon.Get()
scon = NewContext(fileLabel) scon, _ = NewContext(fileLabel)
scon["level"] = mcs scon["level"] = mcs
fileLabel = scon.Get() fileLabel = scon.Get()
} }
@ -661,8 +666,14 @@ func CopyLevel(src, dest string) (string, error) {
if err := SecurityCheckContext(dest); err != nil { if err := SecurityCheckContext(dest); err != nil {
return "", err return "", err
} }
scon := NewContext(src) scon, err := NewContext(src)
tcon := NewContext(dest) if err != nil {
return "", err
}
tcon, err := NewContext(dest)
if err != nil {
return "", err
}
mcsDelete(tcon["level"]) mcsDelete(tcon["level"])
mcsAdd(scon["level"]) mcsAdd(scon["level"])
tcon["level"] = scon["level"] tcon["level"] = scon["level"]
@ -714,15 +725,18 @@ func Chcon(fpath string, label string, recurse bool) error {
// DupSecOpt takes an SELinux process label and returns security options that // DupSecOpt takes an SELinux process label and returns security options that
// can be used to set the SELinux Type and Level for future container processes. // can be used to set the SELinux Type and Level for future container processes.
func DupSecOpt(src string) []string { func DupSecOpt(src string) ([]string, error) {
if src == "" { if src == "" {
return nil return nil, nil
}
con, err := NewContext(src)
if err != nil {
return nil, err
} }
con := NewContext(src)
if con["user"] == "" || if con["user"] == "" ||
con["role"] == "" || con["role"] == "" ||
con["type"] == "" { con["type"] == "" {
return nil return nil, nil
} }
dup := []string{"user:" + con["user"], dup := []string{"user:" + con["user"],
"role:" + con["role"], "role:" + con["role"],
@ -733,7 +747,7 @@ func DupSecOpt(src string) []string {
dup = append(dup, "level:"+con["level"]) dup = append(dup, "level:"+con["level"])
} }
return dup return dup, nil
} }
// DisableSecOpt returns a security opt that can be used to disable SELinux // DisableSecOpt returns a security opt that can be used to disable SELinux

View File

@ -115,9 +115,9 @@ func (c Context) Get() string {
} }
// NewContext creates a new Context struct from the specified label // NewContext creates a new Context struct from the specified label
func NewContext(label string) Context { func NewContext(label string) (Context, error) {
c := make(Context) c := make(Context)
return c return c, nil
} }
// ClearLabels clears all reserved MLS/MCS levels // ClearLabels clears all reserved MLS/MCS levels
@ -195,8 +195,8 @@ func Chcon(fpath string, label string, recurse bool) error {
// DupSecOpt takes an SELinux process label and returns security options that // DupSecOpt takes an SELinux process label and returns security options that
// can be used to set the SELinux Type and Level for future container processes. // can be used to set the SELinux Type and Level for future container processes.
func DupSecOpt(src string) []string { func DupSecOpt(src string) ([]string, error) {
return nil return nil, nil
} }
// DisableSecOpt returns a security opt that can be used to disable SELinux // DisableSecOpt returns a security opt that can be used to disable SELinux