[bug report] ath9k-htc:respect usb buffer cacheline alignment in reg in path

[Dan Carpenter]

Hello Ming Lei,

The patch e6c6d33cb7d1: "ath9k-htc:respect usb buffer cacheline
alignment in reg in path" from Apr 13, 2010, leads to the following
static checker warning:

        drivers/net/wireless/ath/ath9k/hif_usb.c:745 ath9k_hif_usb_reg_in_cb()
        warn: 'skb' was already freed.

drivers/net/wireless/ath/ath9k/hif_usb.c
   712          if (likely(urb->actual_length != 0)) {
   713                  skb_put(skb, urb->actual_length);
   714  
   715                  /* Process the command first */
   716                  ath9k_htc_rx_msg(hif_dev->htc_handle, skb,
   717                                   skb->len, USB_REG_IN_PIPE);
   718  
   719  
   720                  nskb = alloc_skb(MAX_REG_IN_BUF_SIZE, GFP_ATOMIC);
   721                  if (!nskb) {
   722                          dev_err(&hif_dev->udev->dev,
   723                                  "ath9k_htc: REG_IN memory allocation 
failure\n");
   724                          urb->context = NULL;
   725                          return;
   726                  }
   727  
   728                  usb_fill_int_urb(urb, hif_dev->udev,
   729                                   usb_rcvintpipe(hif_dev->udev,
   730                                                   USB_REG_IN_PIPE),
   731                                   nskb->data, MAX_REG_IN_BUF_SIZE,
   732                                   ath9k_hif_usb_reg_in_cb, nskb, 1);
   733          }
   734  
   735  resubmit:
   736          usb_anchor_urb(urb, &hif_dev->reg_in_submitted);
   737          ret = usb_submit_urb(urb, GFP_ATOMIC);
   738          if (ret) {
   739                  usb_unanchor_urb(urb);
   740                  goto free;
   741          }
   742  
   743          return;
   744  free:
   745          kfree_skb(skb);
   746          urb->context = NULL;
   747  }

regards,
dan carpenter