[PATCH v5] staging: rtl8192u: add error handling for usb_alloc_urb

[Zhouyang Jia]

When usb_alloc_urb fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling usb_alloc_urb,
and fixes memory leaks in error paths.

Signed-off-by: Zhouyang Jia <jiazhouyan...@gmail.com>
---
v1->v2:
- Fix memory leak.
v2->v3:
- Release memory in error path.
v3->v4:
- Use kcalloc instead of kmalloc_array.
v4->v5:
- Free priv->rx_urb[i]->transfer_buffer and priv->oldaddr.
---
 drivers/staging/rtl8192u/r8192U_core.c | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/rtl8192u/r8192U_core.c 
b/drivers/staging/rtl8192u/r8192U_core.c
index 7a0dbc0..9413f29 100644
--- a/drivers/staging/rtl8192u/r8192U_core.c
+++ b/drivers/staging/rtl8192u/r8192U_core.c
@@ -1639,8 +1639,9 @@ short rtl8192_tx(struct net_device *dev, struct sk_buff 
*skb)
 static short rtl8192_usb_initendpoints(struct net_device *dev)
 {
        struct r8192_priv *priv = ieee80211_priv(dev);
+       int i;
 
-       priv->rx_urb = kmalloc(sizeof(struct urb *) * (MAX_RX_URB + 1),
+       priv->rx_urb = kcalloc(MAX_RX_URB + 1, sizeof(struct urb *),
                               GFP_KERNEL);
        if (!priv->rx_urb)
                return -ENOMEM;
@@ -1649,12 +1650,12 @@ static short rtl8192_usb_initendpoints(struct 
net_device *dev)
        for (i = 0; i < (MAX_RX_URB + 1); i++) {
                priv->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
                if (!priv->rx_urb[i])
-                       return -ENOMEM;
+                       goto out_release_urb;
 
                priv->rx_urb[i]->transfer_buffer =
                        kmalloc(RX_URB_SIZE, GFP_KERNEL);
                if (!priv->rx_urb[i]->transfer_buffer)
-                       return -ENOMEM;
+                       goto out_release_urb;
 
                priv->rx_urb[i]->transfer_buffer_length = RX_URB_SIZE;
        }
@@ -1666,9 +1667,13 @@ static short rtl8192_usb_initendpoints(struct net_device 
*dev)
                void *oldaddr, *newaddr;
 
                priv->rx_urb[16] = usb_alloc_urb(0, GFP_KERNEL);
+               if (!priv->rx_urb[16])
+                       goto out_release_urb;
+
                priv->oldaddr = kmalloc(16, GFP_KERNEL);
                if (!priv->oldaddr)
-                       return -ENOMEM;
+                       goto out_release_urb;
+
                oldaddr = priv->oldaddr;
                align = ((long)oldaddr) & 3;
                if (align) {
@@ -1686,17 +1691,26 @@ static short rtl8192_usb_initendpoints(struct 
net_device *dev)
        priv->pp_rxskb = kcalloc(MAX_RX_URB, sizeof(struct sk_buff *),
                                 GFP_KERNEL);
        if (!priv->pp_rxskb) {
-               kfree(priv->rx_urb);
-
-               priv->pp_rxskb = NULL;
-               priv->rx_urb = NULL;
-
                DMESGE("Endpoint Alloc Failure");
-               return -ENOMEM;
+               goto out_release_oldaddr;
        }
 
        netdev_dbg(dev, "End of initendpoints\n");
        return 0;
+
+out_release_oldaddr:
+       kfree(priv->oldaddr);
+
+out_release_urb:
+       for (i = 0; i < (MAX_RX_URB + 1); i++) {
+               if (priv->rx_urb[i]) {
+                       kfree(priv->rx_urb[i]->transfer_buffer);
+                       kfree(priv->rx_urb[i]);
+               }
+       }
+       kfree(priv->rx_urb);
+       priv->rx_urb = NULL;
+       return -ENOMEM;
 }
 
 #ifdef THOMAS_BEACON
-- 
2.7.4