Revert "ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb"

BugLink: https://bugs.launchpad.net/bugs/1888690

This reverts commit 90ecba9f1041f436ed2b35ba7a970c7cc5d0df23 which is
commit 2bbcaaee upstream.

It is being reverted upstream, just hasn't made it there yet and is
causing lots of problems.
Reported-by: Hans de Goede <hdegoede@redhat.com>
Cc: Qiujun Huang <hqjagain@gmail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/net/wireless/ath/ath9k/hif_usb.c

@@ -639,9 +639,9 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
 
 static void ath9k_hif_usb_rx_cb(struct urb *urb)
 {
-	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 *skb = (struct sk_buff *) urb->context;
+	struct hif_device_usb *hif_dev =
+		usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
 	int ret;
 
 	if (!skb)
@@ -681,15 +681,14 @@ static void ath9k_hif_usb_rx_cb(struct urb *urb)
 	return;
 free:
 	kfree_skb(skb);
-	kfree(rx_buf);
 }
 
 static void ath9k_hif_usb_reg_in_cb(struct urb *urb)
 {
-	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 *skb = (struct sk_buff *) urb->context;
 	struct sk_buff *nskb;
+	struct hif_device_usb *hif_dev =
+		usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
 	int ret;
 
 	if (!skb)
@@ -747,7 +746,6 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb)
 	return;
 free:
 	kfree_skb(skb);
-	kfree(rx_buf);
 	urb->context = NULL;
 }
 
@@ -793,7 +791,7 @@ static int ath9k_hif_usb_alloc_tx_urbs(struct hif_device_usb *hif_dev)
 	init_usb_anchor(&hif_dev->mgmt_submitted);
 
 	for (i = 0; i < MAX_TX_URB_NUM; i++) {
-		tx_buf = kzalloc(sizeof(*tx_buf), GFP_KERNEL);
+		tx_buf = kzalloc(sizeof(struct tx_buf), GFP_KERNEL);
 		if (!tx_buf)
 			goto err;
 
@@ -830,9 +828,8 @@ static void ath9k_hif_usb_dealloc_rx_urbs(struct hif_device_usb *hif_dev)
 
 static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
 {
-	struct rx_buf *rx_buf = NULL;
-	struct sk_buff *skb = NULL;
 	struct urb *urb = NULL;
+	struct sk_buff *skb = NULL;
 	int i, ret;
 
 	init_usb_anchor(&hif_dev->rx_submitted);
@@ -840,12 +837,6 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
 
 	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) {
@@ -860,14 +851,11 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
 			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, rx_buf);
+				  ath9k_hif_usb_rx_cb, skb);
 
 		/* Anchor URB */
 		usb_anchor_urb(urb, &hif_dev->rx_submitted);
@@ -893,8 +881,6 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
 err_skb:
 	usb_free_urb(urb);
 err_urb:
-	kfree(rx_buf);
-err_rxb:
 	ath9k_hif_usb_dealloc_rx_urbs(hif_dev);
 	return ret;
 }
@@ -906,21 +892,14 @@ static void ath9k_hif_usb_dealloc_reg_in_urbs(struct hif_device_usb *hif_dev)
 
 static int ath9k_hif_usb_alloc_reg_in_urbs(struct hif_device_usb *hif_dev)
 {
-	struct rx_buf *rx_buf = NULL;
-	struct sk_buff *skb = NULL;
 	struct urb *urb = NULL;
+	struct sk_buff *skb = 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) {
@@ -935,14 +914,11 @@ static int ath9k_hif_usb_alloc_reg_in_urbs(struct hif_device_usb *hif_dev)
 			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, rx_buf, 1);
+				  ath9k_hif_usb_reg_in_cb, skb, 1);
 
 		/* Anchor URB */
 		usb_anchor_urb(urb, &hif_dev->reg_in_submitted);
@@ -968,8 +944,6 @@ static int ath9k_hif_usb_alloc_reg_in_urbs(struct hif_device_usb *hif_dev)
 err_skb:
 	usb_free_urb(urb);
 err_urb:
-	kfree(rx_buf);
-err_rxb:
 	ath9k_hif_usb_dealloc_reg_in_urbs(hif_dev);
 	return ret;
 }

drivers/net/wireless/ath/ath9k/hif_usb.h

@@ -84,11 +84,6 @@ 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)