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From:   Zhouyang Jia <jiazhouyang09@gmail.com>
Cc:     Zhouyang Jia <jiazhouyang09@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Jia-Ju Bai <baijiaju1990@gmail.com>,
        Shreeya Patel <shreeya.patel23498@gmail.com>,
        Colin Ian King <colin.king@canonical.com>,
        Kees Cook <keescook@chromium.org>, devel@driverdev.osuosl.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v4] staging: rtl8192u: add error handling for usb_alloc_urb
Date:   Sat, 16 Jun 2018 10:01:22 +0800
Message-Id: <1529114485-60684-1-git-send-email-jiazhouyang09@gmail.com>
In-Reply-To: <1528705874-34845-1-git-send-email-jiazhouyang09@gmail.com>
References: <1528705874-34845-1-git-send-email-jiazhouyang09@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When usb_alloc_urb fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling usb_alloc_urb.

Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
---
v1->v2:
- Fix memory leak.
v2->v3:
- Release memory in error path.
v3->v4:
- Use kcalloc instead of kmalloc_array.
---
 drivers/staging/rtl8192u/r8192U_core.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/rtl8192u/r8192U_core.c b/drivers/staging/rtl8192u/r8192U_core.c
index 7a0dbc0..d15ee4f 100644
--- a/drivers/staging/rtl8192u/r8192U_core.c
+++ b/drivers/staging/rtl8192u/r8192U_core.c
@@ -1639,8 +1639,9 @@ short rtl8192_tx(struct net_device *dev, struct sk_buff *skb)
 static short rtl8192_usb_initendpoints(struct net_device *dev)
 {
 	struct r8192_priv *priv = ieee80211_priv(dev);
+	int i;
 
-	priv->rx_urb = kmalloc(sizeof(struct urb *) * (MAX_RX_URB + 1),
+	priv->rx_urb = kcalloc(MAX_RX_URB + 1, sizeof(struct urb *),
 			       GFP_KERNEL);
 	if (!priv->rx_urb)
 		return -ENOMEM;
@@ -1649,12 +1650,12 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
 	for (i = 0; i < (MAX_RX_URB + 1); i++) {
 		priv->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
 		if (!priv->rx_urb[i])
-			return -ENOMEM;
+			goto out_release_mem;
 
 		priv->rx_urb[i]->transfer_buffer =
 			kmalloc(RX_URB_SIZE, GFP_KERNEL);
 		if (!priv->rx_urb[i]->transfer_buffer)
-			return -ENOMEM;
+			goto out_release_mem;
 
 		priv->rx_urb[i]->transfer_buffer_length = RX_URB_SIZE;
 	}
@@ -1666,9 +1667,13 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
 		void *oldaddr, *newaddr;
 
 		priv->rx_urb[16] = usb_alloc_urb(0, GFP_KERNEL);
+		if (!priv->rx_urb[16])
+			goto out_release_mem;
+
 		priv->oldaddr = kmalloc(16, GFP_KERNEL);
 		if (!priv->oldaddr)
-			return -ENOMEM;
+			goto out_release_mem;
+
 		oldaddr = priv->oldaddr;
 		align = ((long)oldaddr) & 3;
 		if (align) {
@@ -1686,17 +1691,19 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
 	priv->pp_rxskb = kcalloc(MAX_RX_URB, sizeof(struct sk_buff *),
 				 GFP_KERNEL);
 	if (!priv->pp_rxskb) {
-		kfree(priv->rx_urb);
-
-		priv->pp_rxskb = NULL;
-		priv->rx_urb = NULL;
-
 		DMESGE("Endpoint Alloc Failure");
-		return -ENOMEM;
+		goto out_release_mem;
 	}
 
 	netdev_dbg(dev, "End of initendpoints\n");
 	return 0;
+
+out_release_mem:
+	for (i = 0; i < (MAX_RX_URB + 1); i++)
+		kfree(priv->rx_urb[i]);
+	kfree(priv->rx_urb);
+	priv->rx_urb = NULL;
+	return -ENOMEM;
 }
 
 #ifdef THOMAS_BEACON
-- 
2.7.4