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From:   Chris Chiu <chiu@endlessm.com>
To:     Jes.Sorensen@gmail.com, kvalo@codeaurora.org, davem@davemloft.net,
        kuba@kernel.org
Cc:     linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, Chris Chiu <chiu@endlessm.com>
Subject: [PATCH] rtl8xxxu: prevent potential memory leak
Date:   Sun,  6 Sep 2020 12:04:24 +0800
Message-Id: <20200906040424.22022-1-chiu@endlessm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

Free the skb if usb_submit_urb fails on rx_urb. And free the urb
no matter usb_submit_urb succeeds or not in rtl8xxxu_submit_int_urb.

Signed-off-by: Chris Chiu <chiu@endlessm.com>
---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 19efae462a24..5cd7ef3625c5 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -5795,7 +5795,6 @@ static int rtl8xxxu_submit_int_urb(struct ieee80211_hw *hw)
 	ret = usb_submit_urb(urb, GFP_KERNEL);
 	if (ret) {
 		usb_unanchor_urb(urb);
-		usb_free_urb(urb);
 		goto error;
 	}
 
@@ -5804,6 +5803,7 @@ static int rtl8xxxu_submit_int_urb(struct ieee80211_hw *hw)
 	rtl8xxxu_write32(priv, REG_USB_HIMR, val32);
 
 error:
+	usb_free_urb(urb);
 	return ret;
 }
 
@@ -6318,6 +6318,7 @@ static int rtl8xxxu_start(struct ieee80211_hw *hw)
 	struct rtl8xxxu_priv *priv = hw->priv;
 	struct rtl8xxxu_rx_urb *rx_urb;
 	struct rtl8xxxu_tx_urb *tx_urb;
+	struct sk_buff *skb;
 	unsigned long flags;
 	int ret, i;
 
@@ -6368,6 +6369,13 @@ static int rtl8xxxu_start(struct ieee80211_hw *hw)
 		rx_urb->hw = hw;
 
 		ret = rtl8xxxu_submit_rx_urb(priv, rx_urb);
+		if (ret) {
+			if (ret != -ENOMEM) {
+				skb = (struct sk_buff *)rx_urb->urb.context;
+				dev_kfree_skb(skb);
+			}
+			rtl8xxxu_queue_rx_urb(priv, rx_urb);
+		}
 	}
 
 	schedule_delayed_work(&priv->ra_watchdog, 2 * HZ);
-- 
2.20.1