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From:   Wenwen Wang <wenwen@cs.uga.edu>
To:     Wenwen Wang <wenwen@cs.uga.edu>
Cc:     Oliver Neukum <oneukum@suse.com>,
        "David S. Miller" <davem@davemloft.net>,
        netdev@vger.kernel.org (open list:USB "USBNET" DRIVER FRAMEWORK),
        linux-usb@vger.kernel.org (open list:USB NETWORKING DRIVERS),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] net: usbnet: fix a memory leak bug
Date:   Wed, 14 Aug 2019 12:41:33 -0500
Message-Id: <1565804493-7758-1-git-send-email-wenwen@cs.uga.edu>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In usbnet_start_xmit(), 'urb->sg' is allocated through kmalloc_array() by
invoking build_dma_sg(). Later on, if 'CONFIG_PM' is defined and the if
branch is taken, the execution will go to the label 'deferred'. However,
'urb->sg' is not deallocated on this execution path, leading to a memory
leak bug.

Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
---
 drivers/net/usb/usbnet.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 72514c4..f17fafa 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1433,6 +1433,7 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
 		usb_anchor_urb(urb, &dev->deferred);
 		/* no use to process more packets */
 		netif_stop_queue(net);
+		kfree(urb->sg);
 		usb_put_urb(urb);
 		spin_unlock_irqrestore(&dev->txq.lock, flags);
 		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
-- 
2.7.4