diff --git a/libcontainer/integration/exec_test.go b/libcontainer/integration/exec_test.go index ae7ecc41..d8b6e16b 100644 --- a/libcontainer/integration/exec_test.go +++ b/libcontainer/integration/exec_test.go @@ -845,6 +845,15 @@ func TestMountCgroupRO(t *testing.T) { mountInfo := buffers.Stdout.String() lines := strings.Split(mountInfo, "\n") for _, l := range lines { + if strings.HasPrefix(l, "tmpfs on /sys/fs/cgroup") { + if !strings.Contains(l, "ro,nosuid,nodev,noexec") { + t.Fatalf("Mode expected to contain 'ro,nosuid,nodev,noexec': %s", l) + } + if !strings.Contains(l, "mode=755") { + t.Fatalf("Mode expected to contain 'mode=755': %s", l) + } + continue + } if !strings.HasPrefix(l, "cgroup") { continue } @@ -880,6 +889,15 @@ func TestMountCgroupRW(t *testing.T) { mountInfo := buffers.Stdout.String() lines := strings.Split(mountInfo, "\n") for _, l := range lines { + if strings.HasPrefix(l, "tmpfs on /sys/fs/cgroup") { + if !strings.Contains(l, "rw,nosuid,nodev,noexec") { + t.Fatalf("Mode expected to contain 'rw,nosuid,nodev,noexec': %s", l) + } + if !strings.Contains(l, "mode=755") { + t.Fatalf("Mode expected to contain 'mode=755': %s", l) + } + continue + } if !strings.HasPrefix(l, "cgroup") { continue } diff --git a/libcontainer/rootfs_linux.go b/libcontainer/rootfs_linux.go index d0334154..78e51224 100644 --- a/libcontainer/rootfs_linux.go +++ b/libcontainer/rootfs_linux.go @@ -186,6 +186,7 @@ func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error { Device: "tmpfs", Destination: m.Destination, Flags: defaultMountFlags, + Data: "mode=755", } if err := mountToRootfs(tmpfs, rootfs, mountLabel); err != nil { return err @@ -218,6 +219,13 @@ func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error { if err := os.Chdir(cwd); err != nil { return err } + if m.Flags&syscall.MS_RDONLY != 0 { + // remount cgroup root as readonly + rootfsCgroup := filepath.Join(rootfs, m.Destination) + if err := syscall.Mount("", rootfsCgroup, "", defaultMountFlags|syscall.MS_REMOUNT|syscall.MS_RDONLY, ""); err != nil { + return err + } + } default: return fmt.Errorf("unknown mount device %q to %q", m.Device, m.Destination) }