diff --git a/go-selinux/selinux_linux.go b/go-selinux/selinux_linux.go index 2d4e9f8..8cdf1b0 100644 --- a/go-selinux/selinux_linux.go +++ b/go-selinux/selinux_linux.go @@ -18,6 +18,7 @@ import ( "strings" "sync" "syscall" + "golang.org/x/sys/unix" ) @@ -253,6 +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 @@ -264,6 +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 @@ -346,6 +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 { @@ -394,7 +413,7 @@ func SetExecLabel(label string) error { } /* -SetTaskLabel sets the SELinux label for the current thread, or an error. +SetTaskLabel sets the SELinux label for the current thread, or an error. This requires the dyntransition permission. */ func SetTaskLabel(label string) error {