Fix potential containerd panic.

Random-Liu · Random-Liu · commit 7bd8dcd0d30f · 2019-02-05T00:38:02.000-08:00
Signed-off-by: Lantao Liu &lt;lantaol@google.com&gt;
diff --git a/process.go b/process.go
@@ -111,9 +111,11 @@ func (p *process) Start(ctx context.Context) error {
 		ExecID:      p.id,
 	})
 	if err != nil {
-		p.io.Cancel()
-		p.io.Wait()
-		p.io.Close()
+		if p.io != nil {
+			p.io.Cancel()
+			p.io.Wait()
+			p.io.Close()
+		}
 		return errdefs.FromGRPC(err)
 	}
 	p.pid = r.Pid
diff --git a/task.go b/task.go
@@ -189,8 +189,10 @@ func (t *task) Start(ctx context.Context) error {
 		ContainerID: t.id,
 	})
 	if err != nil {
-		t.io.Cancel()
-		t.io.Close()
+		if t.io != nil {
+			t.io.Cancel()
+			t.io.Close()
+		}
 		return errdefs.FromGRPC(err)
 	}
 	t.pid = r.Pid
