diff --git a/runsc/cmd/boot.go b/runsc/cmd/boot.go index 7ca2744bd..fb1fd3e70 100644 --- a/runsc/cmd/boot.go +++ b/runsc/cmd/boot.go @@ -75,6 +75,9 @@ type Boot struct { // startSyncFD is the file descriptor to synchronize runsc and sandbox. startSyncFD int + + // pidns is set if the sanadbox is in its own pid namespace. + pidns bool } // Name implements subcommands.Command.Name. @@ -103,6 +106,7 @@ func (b *Boot) SetFlags(f *flag.FlagSet) { f.BoolVar(&b.console, "console", false, "set to true if the sandbox should allow terminal ioctl(2) syscalls") f.BoolVar(&b.applyCaps, "apply-caps", false, "if true, apply capabilities defined in the spec to the process") f.BoolVar(&b.setUpRoot, "setup-root", false, "if true, set up an empty root for the process") + f.BoolVar(&b.pidns, "pidns", false, "if true, the sandbox is in its own PID namespace") f.IntVar(&b.cpuNum, "cpu-num", 0, "number of CPUs to create inside the sandbox") f.Uint64Var(&b.totalMem, "total-memory", 0, "sets the initial amount of total memory to report back to the container") f.IntVar(&b.userLogFD, "user-log-fd", 0, "file descriptor to write user logs to. 0 means no logging.") @@ -121,7 +125,7 @@ func (b *Boot) Execute(_ context.Context, f *flag.FlagSet, args ...interface{}) debug.SetTraceback("all") if b.setUpRoot { - if err := setUpChroot(); err != nil { + if err := setUpChroot(b.pidns); err != nil { Fatalf("error setting up chroot: %v", err) } diff --git a/runsc/cmd/chroot.go b/runsc/cmd/chroot.go index b53085934..ec539a11c 100644 --- a/runsc/cmd/chroot.go +++ b/runsc/cmd/chroot.go @@ -42,7 +42,7 @@ func mountInChroot(chroot, src, dst, typ string, flags uint32) error { // setUpChroot creates an empty directory with runsc mounted at /runsc and proc // mounted at /proc. -func setUpChroot() error { +func setUpChroot(pidns bool) error { // We are a new mount namespace, so we can use /tmp as a directory to // construct a new root. chroot := os.TempDir() @@ -59,8 +59,15 @@ func setUpChroot() error { return fmt.Errorf("error mounting tmpfs in choot: %v", err) } - if err := mountInChroot(chroot, "/proc", "/proc", "bind", syscall.MS_BIND|syscall.MS_RDONLY|syscall.MS_REC); err != nil { - return fmt.Errorf("error mounting proc in chroot: %v", err) + if pidns { + flags := uint32(syscall.MS_NOSUID | syscall.MS_NODEV | syscall.MS_NOEXEC | syscall.MS_RDONLY) + if err := mountInChroot(chroot, "proc", "/proc", "proc", flags); err != nil { + return fmt.Errorf("error mounting proc in chroot: %v", err) + } + } else { + if err := mountInChroot(chroot, "/proc", "/proc", "bind", syscall.MS_BIND|syscall.MS_RDONLY|syscall.MS_REC); err != nil { + return fmt.Errorf("error mounting proc in chroot: %v", err) + } } if err := mountInChroot(chroot, specutils.ExePath, chrootBinPath, "bind", syscall.MS_BIND|syscall.MS_RDONLY); err != nil { diff --git a/runsc/sandbox/sandbox.go b/runsc/sandbox/sandbox.go index 411200793..d28d93b0a 100644 --- a/runsc/sandbox/sandbox.go +++ b/runsc/sandbox/sandbox.go @@ -458,6 +458,7 @@ func (s *Sandbox) createSandboxProcess(spec *specs.Spec, conf *boot.Config, bund } else { log.Infof("Sandbox will be started in a new PID namespace") nss = append(nss, specs.LinuxNamespace{Type: specs.PIDNamespace}) + cmd.Args = append(cmd.Args, "--pidns=true") } // Joins the network namespace if network is enabled. the sandbox talks