Re: [PATCH v3] staging: vt6655: check for memory allocation failures

[Jia-Ju Bai]

On 2018/3/30 10:44, Ji-Hun Kim wrote:
@@ -1165,10 +1205,18 @@ static int vnt_start(struct ieee80211_hw *hw)
        }
  
  	dev_dbg(&priv->pcid->dev, "call device init rd0 ring\n");
-       device_init_rd0_ring(priv);
-       device_init_rd1_ring(priv);
-       device_init_td0_ring(priv);
-       device_init_td1_ring(priv);
+       ret = device_init_rd0_ring(priv);
+       if (ret)
+               goto error;
+       ret = device_init_rd1_ring(priv);
+       if (ret)
+               goto error;
+       ret = device_init_td0_ring(priv);
+       if (ret)
+               goto error;
+       ret = device_init_td1_ring(priv);
+       if (ret)
+               goto error;
  
  	device_init_registers(priv);
  
@@ -1178,6 +1226,8 @@ static int vnt_start(struct ieee80211_hw *hw)
        ieee80211_wake_queues(hw);
  
  	return 0;
+error:
+       return ret;
  }

This code will lead to memory leaks when device_init_rd1_ring() fails, 
because the memory allocated by device_init_rd0_ring() is not freed.

I think this one will be better:
    ret = device_init_rd0_ring(priv);
    if (ret)
        goto error_init_rd0_ring;
    ret = device_init_rd1_ring(priv);
    if (ret)
        goto error_init_rd1_ring;
    ret = device_init_td0_ring(priv);
    if (ret)
        goto error_init_td0_ring;
    ret = device_init_td1_ring(priv);
    if (ret)
        goto error_init_td1_ring;
    ......
error_init_td1_ring:
    device_free_td0_ring(priv);
error_init_td0_ring:
    device_free_rd1_ring(priv);
error_init_rd1_ring:
    device_free_rd0_ring(priv);
error_init_rd0_ring:
    return ret;


Best wishes,
Jia-Ju Bai