release/4.8.22/rtlwifi-rtl_usb-Fix-for-URB-leaking-when-doing-ifcon.patch

From 11cda0677175d1b72176eb9b25d8c08c48a8d2d0 Mon Sep 17 00:00:00 2001
From: Michael Schenk <michael.schenk@albis-elcon.com>
Date: Thu, 26 Jan 2017 11:25:04 -0600
Subject: [PATCH] rtlwifi: rtl_usb: Fix for URB leaking when doing ifconfig
 up/down

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.

Signed-off-by: Michael Schenk <michael.schenk@albis-elcon.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/net/wireless/realtek/rtlwifi/usb.c b/drivers/net/wireless/realtek/rtlwifi/usb.c
index 41617b7b0822..5412074c0e89 100644
--- a/drivers/net/wireless/realtek/rtlwifi/usb.c
+++ b/drivers/net/wireless/realtek/rtlwifi/usb.c
@@ -834,12 +834,30 @@ static void rtl_usb_stop(struct ieee80211_hw *hw)
 	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);
 }
 
-- 
2.12.0