[4.9,046/128] ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb

--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -641,9 +641,9 @@  err:
 
 static void ath9k_hif_usb_rx_cb(struct urb *urb)
 {
-	struct sk_buff *skb = (struct sk_buff *) urb->context;
-	struct hif_device_usb *hif_dev =
-		usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
+	struct rx_buf *rx_buf = (struct rx_buf *)urb->context;
+	struct hif_device_usb *hif_dev = rx_buf->hif_dev;
+	struct sk_buff *skb = rx_buf->skb;
 	int ret;
 
 	if (!skb)
@@ -683,14 +683,15 @@  resubmit:
 	return;
 free:
 	kfree_skb(skb);
+	kfree(rx_buf);
 }
 
 static void ath9k_hif_usb_reg_in_cb(struct urb *urb)
 {
-	struct sk_buff *skb = (struct sk_buff *) urb->context;
+	struct rx_buf *rx_buf = (struct rx_buf *)urb->context;
+	struct hif_device_usb *hif_dev = rx_buf->hif_dev;
+	struct sk_buff *skb = rx_buf->skb;
 	struct sk_buff *nskb;
-	struct hif_device_usb *hif_dev =
-		usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
 	int ret;
 
 	if (!skb)
@@ -748,6 +749,7 @@  resubmit:
 	return;
 free:
 	kfree_skb(skb);
+	kfree(rx_buf);
 	urb->context = NULL;
 }
 
@@ -793,7 +795,7 @@  static int ath9k_hif_usb_alloc_tx_urbs(s
 	init_usb_anchor(&hif_dev->mgmt_submitted);
 
 	for (i = 0; i < MAX_TX_URB_NUM; i++) {
-		tx_buf = kzalloc(sizeof(struct tx_buf), GFP_KERNEL);
+		tx_buf = kzalloc(sizeof(*tx_buf), GFP_KERNEL);
 		if (!tx_buf)
 			goto err;
 
@@ -830,8 +832,9 @@  static void ath9k_hif_usb_dealloc_rx_urb
 
 static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
 {
-	struct urb *urb = NULL;
+	struct rx_buf *rx_buf = NULL;
 	struct sk_buff *skb = NULL;
+	struct urb *urb = NULL;
 	int i, ret;
 
 	init_usb_anchor(&hif_dev->rx_submitted);
@@ -839,6 +842,12 @@  static int ath9k_hif_usb_alloc_rx_urbs(s
 
 	for (i = 0; i < MAX_RX_URB_NUM; i++) {
 
+		rx_buf = kzalloc(sizeof(*rx_buf), GFP_KERNEL);
+		if (!rx_buf) {
+			ret = -ENOMEM;
+			goto err_rxb;
+		}
+
 		/* Allocate URB */
 		urb = usb_alloc_urb(0, GFP_KERNEL);
 		if (urb == NULL) {
@@ -853,11 +862,14 @@  static int ath9k_hif_usb_alloc_rx_urbs(s
 			goto err_skb;
 		}
 
+		rx_buf->hif_dev = hif_dev;
+		rx_buf->skb = skb;
+
 		usb_fill_bulk_urb(urb, hif_dev->udev,
 				  usb_rcvbulkpipe(hif_dev->udev,
 						  USB_WLAN_RX_PIPE),
 				  skb->data, MAX_RX_BUF_SIZE,
-				  ath9k_hif_usb_rx_cb, skb);
+				  ath9k_hif_usb_rx_cb, rx_buf);
 
 		/* Anchor URB */
 		usb_anchor_urb(urb, &hif_dev->rx_submitted);
@@ -883,6 +895,8 @@  err_submit:
 err_skb:
 	usb_free_urb(urb);
 err_urb:
+	kfree(rx_buf);
+err_rxb:
 	ath9k_hif_usb_dealloc_rx_urbs(hif_dev);
 	return ret;
 }
@@ -894,14 +908,21 @@  static void ath9k_hif_usb_dealloc_reg_in
 
 static int ath9k_hif_usb_alloc_reg_in_urbs(struct hif_device_usb *hif_dev)
 {
-	struct urb *urb = NULL;
+	struct rx_buf *rx_buf = NULL;
 	struct sk_buff *skb = NULL;
+	struct urb *urb = NULL;
 	int i, ret;
 
 	init_usb_anchor(&hif_dev->reg_in_submitted);
 
 	for (i = 0; i < MAX_REG_IN_URB_NUM; i++) {
 
+		rx_buf = kzalloc(sizeof(*rx_buf), GFP_KERNEL);
+		if (!rx_buf) {
+			ret = -ENOMEM;
+			goto err_rxb;
+		}
+
 		/* Allocate URB */
 		urb = usb_alloc_urb(0, GFP_KERNEL);
 		if (urb == NULL) {
@@ -916,11 +937,14 @@  static int ath9k_hif_usb_alloc_reg_in_ur
 			goto err_skb;
 		}
 
+		rx_buf->hif_dev = hif_dev;
+		rx_buf->skb = skb;
+
 		usb_fill_int_urb(urb, hif_dev->udev,
 				  usb_rcvintpipe(hif_dev->udev,
 						  USB_REG_IN_PIPE),
 				  skb->data, MAX_REG_IN_BUF_SIZE,
-				  ath9k_hif_usb_reg_in_cb, skb, 1);
+				  ath9k_hif_usb_reg_in_cb, rx_buf, 1);
 
 		/* Anchor URB */
 		usb_anchor_urb(urb, &hif_dev->reg_in_submitted);
@@ -946,6 +970,8 @@  err_submit:
 err_skb:
 	usb_free_urb(urb);
 err_urb:
+	kfree(rx_buf);
+err_rxb:
 	ath9k_hif_usb_dealloc_reg_in_urbs(hif_dev);
 	return ret;
 }
--- a/drivers/net/wireless/ath/ath9k/hif_usb.h
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.h
@@ -84,6 +84,11 @@  struct tx_buf {
 	struct list_head list;
 };
 
+struct rx_buf {
+	struct sk_buff *skb;
+	struct hif_device_usb *hif_dev;
+};
+
 #define HIF_USB_TX_STOP  BIT(0)
 #define HIF_USB_TX_FLUSH BIT(1)