Pick up fix for CVE-2019-16884 in opencontainers/selinux

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

vendor/github.com/opencontainers/selinux/go-selinux/label/label_selinux.go

@@ -13,11 +13,12 @@ import (
 
 // Valid Label Options
 var validOptions = map[string]bool{
-	"disable": true,
-	"type":    true,
-	"user":    true,
-	"role":    true,
-	"level":   true,
+	"disable":  true,
+	"type":     true,
+	"filetype": true,
+	"user":     true,
+	"role":     true,
+	"level":    true,
 }
 
 var ErrIncompatibleLabel = fmt.Errorf("Bad SELinux option z and Z can not be used together")
@@ -51,13 +52,16 @@ func InitLabels(options []string) (plabel string, mlabel string, Err error) {
 				return "", mountLabel, nil
 			}
 			if i := strings.Index(opt, ":"); i == -1 {
-				return "", "", fmt.Errorf("Bad label option %q, valid options 'disable' or \n'user, role, level, type' followed by ':' and a value", opt)
+				return "", "", fmt.Errorf("Bad label option %q, valid options 'disable' or \n'user, role, level, type, filetype' followed by ':' and a value", opt)
 			}
 			con := strings.SplitN(opt, ":", 2)
 			if !validOptions[con[0]] {
-				return "", "", fmt.Errorf("Bad label option %q, valid options 'disable, user, role, level, type'", con[0])
+				return "", "", fmt.Errorf("Bad label option %q, valid options 'disable, user, role, level, type, filetype'", con[0])
 
 			}
+			if con[0] == "filetype" {
+				mcon["type"] = con[1]
+			}
 			pcon[con[0]] = con[1]
 			if con[0] == "level" || con[0] == "user" {
 				mcon[con[0]] = con[1]

vendor/github.com/opencontainers/selinux/go-selinux/selinux_linux.go

@@ -18,6 +18,8 @@ import (
 	"strings"
 	"sync"
 	"syscall"
+
+	"golang.org/x/sys/unix"
 )
 
 const (
@@ -252,6 +254,12 @@ func getSELinuxPolicyRoot() string {
 	return filepath.Join(selinuxDir, readConfig(selinuxTypeTag))
 }
 
+func isProcHandle(fh *os.File) (bool, error) {
+	var buf unix.Statfs_t
+	err := unix.Fstatfs(int(fh.Fd()), &buf)
+	return buf.Type == unix.PROC_SUPER_MAGIC, err
+}
+
 func readCon(fpath string) (string, error) {
 	if fpath == "" {
 		return "", ErrEmptyPath
@@ -263,6 +271,12 @@ func readCon(fpath string) (string, error) {
 	}
 	defer in.Close()
 
+	if ok, err := isProcHandle(in); err != nil {
+		return "", err
+	} else if !ok {
+		return "", fmt.Errorf("%s not on procfs", fpath)
+	}
+
 	var retval string
 	if _, err := fmt.Fscanf(in, "%s", &retval); err != nil {
 		return "", err
@@ -345,6 +359,12 @@ func writeCon(fpath string, val string) error {
 	}
 	defer out.Close()
 
+	if ok, err := isProcHandle(out); err != nil {
+		return err
+	} else if !ok {
+		return fmt.Errorf("%s not on procfs", fpath)
+	}
+
 	if val != "" {
 		_, err = out.Write([]byte(val))
 	} else {
@@ -392,6 +412,14 @@ func SetExecLabel(label string) error {
 	return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/exec", syscall.Gettid()), label)
 }
 
+/*
+SetTaskLabel sets the SELinux label for the current thread, or an error.
+This requires the dyntransition permission.
+*/
+func SetTaskLabel(label string) error {
+	return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/current", syscall.Gettid()), label)
+}
+
 // SetSocketLabel takes a process label and tells the kernel to assign the
 // label to the next socket that gets created
 func SetSocketLabel(label string) error {
@@ -403,6 +431,11 @@ func SocketLabel() (string, error) {
 	return readCon(fmt.Sprintf("/proc/self/task/%d/attr/sockcreate", syscall.Gettid()))
 }
 
+// PeerLabel retrieves the label of the client on the other side of a socket
+func PeerLabel(fd uintptr) (string, error) {
+	return unix.GetsockoptString(int(fd), syscall.SOL_SOCKET, syscall.SO_PEERSEC)
+}
+
 // SetKeyLabel takes a process label and tells the kernel to assign the
 // label to the next kernel keyring that gets created
 func SetKeyLabel(label string) error {

vendor/github.com/opencontainers/selinux/go-selinux/selinux_stub.go

@@ -96,6 +96,14 @@ func SetExecLabel(label string) error {
 	return nil
 }
 
+/*
+SetTaskLabel sets the SELinux label for the current thread, or an error.
+This requires the dyntransition permission.
+*/
+func SetTaskLabel(label string) error {
+        return nil
+}
+
 /*
 SetSocketLabel sets the SELinux label that the kernel will use for any programs
 that are executed by the current process thread, or an error.
@@ -109,6 +117,11 @@ func SocketLabel() (string, error) {
 	return "", nil
 }
 
+// PeerLabel retrieves the label of the client on the other side of a socket
+func PeerLabel(fd uintptr) (string, error) {
+	return "", nil
+}
+
 // SetKeyLabel takes a process label and tells the kernel to assign the
 // label to the next kernel keyring that gets created
 func SetKeyLabel(label string) error {