Merge pull request #40597 from thaJeztah/bump_selinux

vendor: update opencontainers/selinux v1.3.3
This commit is contained in:
Sebastiaan van Stijn 2020-03-02 16:54:47 +01:00 committed by GitHub
commit 501f103a0e
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3 changed files with 87 additions and 110 deletions

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@ -161,6 +161,6 @@ github.com/morikuni/aec 39771216ff4c63d11f5e604076f9
# metrics
github.com/docker/go-metrics b619b3592b65de4f087d9f16863a7e6ff905973c # v0.0.1
github.com/opencontainers/selinux 4defb1c884d2f4f9c890c615380f20f7fc215cf3 # v1.3.1
github.com/opencontainers/selinux 31f70552238c5e017d78c3f1ba65e85f593f48e0 # v1.3.3
# DO NOT EDIT BELOW THIS LINE -------- reserved for downstream projects --------

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@ -11,6 +11,7 @@ import (
"io"
"io/ioutil"
"os"
"path"
"path/filepath"
"regexp"
"strconv"
@ -37,15 +38,14 @@ const (
selinuxTag = "SELINUX"
xattrNameSelinux = "security.selinux"
stRdOnly = 0x01
selinuxfsMagic = 0xf97cff8c
)
type selinuxState struct {
enabledSet bool
enabled bool
selinuxfsSet bool
selinuxfs string
mcsList map[string]bool
enabledSet bool
enabled bool
selinuxfsOnce sync.Once
selinuxfs string
mcsList map[string]bool
sync.Mutex
}
@ -62,6 +62,10 @@ var (
state = selinuxState{
mcsList: make(map[string]bool),
}
// for attrPath()
attrPathOnce sync.Once
haveThreadSelf bool
)
// Context is a representation of the SELinux label broken into 4 parts
@ -98,14 +102,6 @@ func SetDisabled() {
state.setEnable(false)
}
func (s *selinuxState) setSELinuxfs(selinuxfs string) string {
s.Lock()
defer s.Unlock()
s.selinuxfsSet = true
s.selinuxfs = selinuxfs
return s.selinuxfs
}
func verifySELinuxfsMount(mnt string) bool {
var buf syscall.Statfs_t
for {
@ -118,7 +114,8 @@ func verifySELinuxfsMount(mnt string) bool {
}
return false
}
if uint32(buf.Type) != uint32(selinuxfsMagic) {
if uint32(buf.Type) != uint32(unix.SELINUX_MAGIC) {
return false
}
if (buf.Flags & stRdOnly) != 0 {
@ -166,33 +163,29 @@ func findSELinuxfs() string {
// if there is one, or an empty string in case of EOF or error.
func findSELinuxfsMount(s *bufio.Scanner) string {
for s.Scan() {
txt := s.Text()
txt := s.Bytes()
// The first field after - is fs type.
// Safe as spaces in mountpoints are encoded as \040
if !strings.Contains(txt, " - selinuxfs ") {
if !bytes.Contains(txt, []byte(" - selinuxfs ")) {
continue
}
const mPos = 5 // mount point is 5th field
fields := strings.SplitN(txt, " ", mPos+1)
fields := bytes.SplitN(txt, []byte(" "), mPos+1)
if len(fields) < mPos+1 {
continue
}
return fields[mPos-1]
return string(fields[mPos-1])
}
return ""
}
func (s *selinuxState) getSELinuxfs() string {
s.Lock()
selinuxfs := s.selinuxfs
selinuxfsSet := s.selinuxfsSet
s.Unlock()
if selinuxfsSet {
return selinuxfs
}
s.selinuxfsOnce.Do(func() {
s.selinuxfs = findSELinuxfs()
})
return s.setSELinuxfs(findSELinuxfs())
return s.selinuxfs
}
// getSelinuxMountPoint returns the path to the mountpoint of an selinuxfs
@ -254,10 +247,17 @@ func getSELinuxPolicyRoot() string {
return filepath.Join(selinuxDir, readConfig(selinuxTypeTag))
}
func isProcHandle(fh *os.File) (bool, error) {
func isProcHandle(fh *os.File) error {
var buf unix.Statfs_t
err := unix.Fstatfs(int(fh.Fd()), &buf)
return buf.Type == unix.PROC_SUPER_MAGIC, err
if err != nil {
return fmt.Errorf("statfs(%q) failed: %v", fh.Name(), err)
}
if buf.Type != unix.PROC_SUPER_MAGIC {
return fmt.Errorf("file %q is not on procfs", fh.Name())
}
return nil
}
func readCon(fpath string) (string, error) {
@ -271,10 +271,8 @@ func readCon(fpath string) (string, error) {
}
defer in.Close()
if ok, err := isProcHandle(in); err != nil {
if err := isProcHandle(in); err != nil {
return "", err
} else if !ok {
return "", fmt.Errorf("%s not on procfs", fpath)
}
var retval string
@ -317,7 +315,7 @@ SetFSCreateLabel tells kernel the label to create all file system objects
created by this task. Setting label="" to return to default.
*/
func SetFSCreateLabel(label string) error {
return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/fscreate", syscall.Gettid()), label)
return writeAttr("fscreate", label)
}
/*
@ -325,12 +323,12 @@ FSCreateLabel returns the default label the kernel which the kernel is using
for file system objects created by this task. "" indicates default.
*/
func FSCreateLabel() (string, error) {
return readCon(fmt.Sprintf("/proc/self/task/%d/attr/fscreate", syscall.Gettid()))
return readAttr("fscreate")
}
// CurrentLabel returns the SELinux label of the current process thread, or an error.
func CurrentLabel() (string, error) {
return readCon(fmt.Sprintf("/proc/self/task/%d/attr/current", syscall.Gettid()))
return readAttr("current")
}
// PidLabel returns the SELinux label of the given pid, or an error.
@ -343,10 +341,10 @@ ExecLabel returns the SELinux label that the kernel will use for any programs
that are executed by the current process thread, or an error.
*/
func ExecLabel() (string, error) {
return readCon(fmt.Sprintf("/proc/self/task/%d/attr/exec", syscall.Gettid()))
return readAttr("exec")
}
func writeCon(fpath string, val string) error {
func writeCon(fpath, val string) error {
if fpath == "" {
return ErrEmptyPath
}
@ -362,10 +360,8 @@ func writeCon(fpath string, val string) error {
}
defer out.Close()
if ok, err := isProcHandle(out); err != nil {
if err := isProcHandle(out); err != nil {
return err
} else if !ok {
return fmt.Errorf("%s not on procfs", fpath)
}
if val != "" {
@ -379,6 +375,32 @@ func writeCon(fpath string, val string) error {
return nil
}
func attrPath(attr string) string {
// Linux >= 3.17 provides this
const threadSelfPrefix = "/proc/thread-self/attr"
attrPathOnce.Do(func() {
st, err := os.Stat(threadSelfPrefix)
if err == nil && st.Mode().IsDir() {
haveThreadSelf = true
}
})
if haveThreadSelf {
return path.Join(threadSelfPrefix, attr)
}
return path.Join("/proc/self/task/", strconv.Itoa(syscall.Gettid()), "/attr/", attr)
}
func readAttr(attr string) (string, error) {
return readCon(attrPath(attr))
}
func writeAttr(attr, val string) error {
return writeCon(attrPath(attr), val)
}
/*
CanonicalizeContext takes a context string and writes it to the kernel
the function then returns the context that the kernel will use. This function
@ -415,7 +437,7 @@ SetExecLabel sets the SELinux label that the kernel will use for any programs
that are executed by the current process thread, or an error.
*/
func SetExecLabel(label string) error {
return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/exec", syscall.Gettid()), label)
return writeAttr("exec", label)
}
/*
@ -423,18 +445,18 @@ 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)
return writeAttr("current", 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 {
return writeCon(fmt.Sprintf("/proc/self/task/%d/attr/sockcreate", syscall.Gettid()), label)
return writeAttr("sockcreate", label)
}
// SocketLabel retrieves the current socket label setting
func SocketLabel() (string, error) {
return readCon(fmt.Sprintf("/proc/self/task/%d/attr/sockcreate", syscall.Gettid()))
return readAttr("sockcreate")
}
// PeerLabel retrieves the label of the client on the other side of a socket
@ -449,7 +471,7 @@ func SetKeyLabel(label string) error {
if os.IsNotExist(err) {
return nil
}
if label == "" && os.IsPermission(err) && !GetEnabled() {
if label == "" && os.IsPermission(err) {
return nil
}
return err
@ -505,19 +527,18 @@ func ReserveLabel(label string) {
}
func selinuxEnforcePath() string {
return fmt.Sprintf("%s/enforce", getSelinuxMountPoint())
return path.Join(getSelinuxMountPoint(), "enforce")
}
// EnforceMode returns the current SELinux mode Enforcing, Permissive, Disabled
func EnforceMode() int {
var enforce int
enforceS, err := readCon(selinuxEnforcePath())
enforceB, err := ioutil.ReadFile(selinuxEnforcePath())
if err != nil {
return -1
}
enforce, err = strconv.Atoi(string(enforceS))
enforce, err = strconv.Atoi(string(enforceB))
if err != nil {
return -1
}
@ -529,7 +550,7 @@ SetEnforceMode sets the current SELinux mode Enforcing, Permissive.
Disabled is not valid, since this needs to be set at boot time.
*/
func SetEnforceMode(mode int) error {
return writeCon(selinuxEnforcePath(), fmt.Sprintf("%d", mode))
return ioutil.WriteFile(selinuxEnforcePath(), []byte(strconv.Itoa(mode)), 0644)
}
/*
@ -711,7 +732,7 @@ exit:
// SecurityCheckContext validates that the SELinux label is understood by the kernel
func SecurityCheckContext(val string) error {
return writeCon(fmt.Sprintf("%s/context", getSelinuxMountPoint()), val)
return ioutil.WriteFile(path.Join(getSelinuxMountPoint(), "context"), []byte(val), 0644)
}
/*

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@ -3,76 +3,32 @@
package selinux
import (
"syscall"
"unsafe"
"golang.org/x/sys/unix"
)
var _zero uintptr
// Returns a []byte slice if the xattr is set and nil otherwise
// Requires path and its attribute as arguments
func lgetxattr(path string, attr string) ([]byte, error) {
var sz int
pathBytes, err := syscall.BytePtrFromString(path)
if err != nil {
return nil, err
}
attrBytes, err := syscall.BytePtrFromString(attr)
if err != nil {
return nil, err
}
// Start with a 128 length byte array
sz = 128
dest := make([]byte, sz)
destBytes := unsafe.Pointer(&dest[0])
_sz, _, errno := syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
dest := make([]byte, 128)
sz, errno := unix.Lgetxattr(path, attr, dest)
if errno == unix.ERANGE {
// Buffer too small, get the real size first
sz, errno = unix.Lgetxattr(path, attr, []byte{})
if errno != nil {
return nil, errno
}
switch {
case errno == syscall.ENODATA:
return nil, errno
case errno == syscall.ENOTSUP:
return nil, errno
case errno == syscall.ERANGE:
// 128 byte array might just not be good enough,
// A dummy buffer is used ``uintptr(0)`` to get real size
// of the xattrs on disk
_sz, _, errno = syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(unsafe.Pointer(nil)), uintptr(0), 0, 0)
sz = int(_sz)
if sz < 0 {
return nil, errno
}
dest = make([]byte, sz)
destBytes := unsafe.Pointer(&dest[0])
_sz, _, errno = syscall.Syscall6(syscall.SYS_LGETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(destBytes), uintptr(len(dest)), 0, 0)
if errno != 0 {
return nil, errno
}
case errno != 0:
sz, errno = unix.Lgetxattr(path, attr, dest)
}
if errno != nil {
return nil, errno
}
sz = int(_sz)
return dest[:sz], nil
}
func lsetxattr(path string, attr string, data []byte, flags int) error {
pathBytes, err := syscall.BytePtrFromString(path)
if err != nil {
return err
}
attrBytes, err := syscall.BytePtrFromString(attr)
if err != nil {
return err
}
var dataBytes unsafe.Pointer
if len(data) > 0 {
dataBytes = unsafe.Pointer(&data[0])
} else {
dataBytes = unsafe.Pointer(&_zero)
}
_, _, errno := syscall.Syscall6(syscall.SYS_LSETXATTR, uintptr(unsafe.Pointer(pathBytes)), uintptr(unsafe.Pointer(attrBytes)), uintptr(dataBytes), uintptr(len(data)), uintptr(flags), 0)
if errno != 0 {
return errno
}
return nil
return unix.Lsetxattr(path, attr, data, flags)
}