net: usb: Fix memory leak on Tx data path
Driver anchors the tx urbs and defers the urb submission if
a transmit request comes when the interface is suspended.
Anchoring urb increments the urb reference count. These
deferred urbs are later accessed by calling usb_get_from_anchor()
for submission during interface resume. usb_get_from_anchor()
unanchors the urb but urb reference count remains same.
This causes the urb reference count to remain non-zero
after usb_free_urb() gets called and urb never gets freed.
Hence call usb_put_urb() after anchoring the urb to properly
balance the reference count for these deferred urbs. Also,
unanchor these deferred urbs during disconnect, to free them
up.
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index f9819d1..cb04f90 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1158,6 +1158,7 @@
usb_anchor_urb(urb, &dev->deferred);
/* no use to process more packets */
netif_stop_queue(net);
+ usb_put_urb(urb);
spin_unlock_irqrestore(&dev->txq.lock, flags);
netdev_dbg(dev->net, "Delaying transmission for resumption\n");
goto deferred;
@@ -1310,6 +1311,8 @@
cancel_work_sync(&dev->kevent);
+ usb_scuttle_anchored_urbs(&dev->deferred);
+
if (dev->driver_info->unbind)
dev->driver_info->unbind (dev, intf);