Patch "rtlwifi: rtl_usb: Fix for URB leaking when doing ifconfig up/down" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

rtlwifi: rtl_usb: Fix for URB leaking when doing ifconfig up/down

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
rtlwifi-rtl_usb-fix-for-urb-leaking-when-doing-ifconfig-up-down.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Michael Schenk <[email protected]>
Date: Thu, 26 Jan 2017 11:25:04 -0600
Subject: rtlwifi: rtl_usb: Fix for URB leaking when doing ifconfig up/down

From: Michael Schenk <[email protected]>

commit 575ddce0507789bf9830d089557d2199d2f91865 upstream.

In the function rtl_usb_start we pre-allocate a certain number of urbs for RX path but they will not be freed when calling rtl_usb_stop. This results in leaking urbs when doing ifconfig up and down. Eventually, the system has no available urbs.

---
 drivers/net/wireless/realtek/rtlwifi/usb.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

@@ -834,12 +834,30 @@ static void rtl_usb_stop(struct ieee8021
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct rtl_hal *rtlhal = rtl_hal(rtl_priv(hw));
 	struct rtl_usb *rtlusb = rtl_usbdev(rtl_usbpriv(hw));
+	struct urb *urb;
 
 	/* should after adapter start and interrupt enable. */
 	set_hal_stop(rtlhal);
 	cancel_work_sync(&rtlpriv->works.fill_h2c_cmd);
 	/* Enable software */
 	SET_USB_STOP(rtlusb);
+
+	/* free pre-allocated URBs from rtl_usb_start() */
+	usb_kill_anchored_urbs(&rtlusb->rx_submitted);
+
+	tasklet_kill(&rtlusb->rx_work_tasklet);
+	cancel_work_sync(&rtlpriv->works.lps_change_work);
+
+	flush_workqueue(rtlpriv->works.rtl_wq);
+
+	skb_queue_purge(&rtlusb->rx_queue);
+
+	while ((urb = usb_get_from_anchor(&rtlusb->rx_cleanup_urbs))) {
+		usb_free_coherent(urb->dev, urb->transfer_buffer_length,
+				urb->transfer_buffer, urb->transfer_dma);
+		usb_free_urb(urb);
+	}
+
 	rtlpriv->cfg->ops->hw_disable(hw);
 }
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/rtlwifi-rtl_usb-fix-for-urb-leaking-when-doing-ifconfig-up-down.patch