linux-kernel - [PATCH] can: usb_8dev: fix possible double dev_kfree_skb in usb_8dev_start

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220311080614.45229-1-hbh25y@gmail.com>
Date:   Fri, 11 Mar 2022 16:06:14 +0800
From:   Hangyu Hua <hbh25y@...il.com>
To:     wg@...ndegger.com, mkl@...gutronix.de, davem@...emloft.net,
        kuba@...nel.org, stefan.maetje@....eu, mailhol.vincent@...adoo.fr,
        paskripkin@...il.com, b.krumboeck@...il.com
Cc:     linux-can@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, Hangyu Hua <hbh25y@...il.com>
Subject: [PATCH] can: usb_8dev: fix possible double dev_kfree_skb in usb_8dev_start_xmit

There is no need to call dev_kfree_skb when usb_submit_urb fails beacause
can_put_echo_skb deletes original skb and can_free_echo_skb deletes the cloned
skb.

Fixes: 0024d8ad1639 ("can: usb_8dev: Add support for USB2CAN interface from 8 devices")
Signed-off-by: Hangyu Hua <hbh25y@...il.com>
---
 drivers/net/can/usb/usb_8dev.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
index 431af1ec1e3c..b638604bf1ee 100644
--- a/drivers/net/can/usb/usb_8dev.c
+++ b/drivers/net/can/usb/usb_8dev.c
@@ -663,9 +663,20 @@ static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 	atomic_inc(&priv->active_tx_urbs);
 
 	err = usb_submit_urb(urb, GFP_ATOMIC);
-	if (unlikely(err))
-		goto failed;
-	else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
+	if (unlikely(err)) {
+		can_free_echo_skb(netdev, context->echo_index, NULL);
+
+		usb_unanchor_urb(urb);
+		usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
+
+		atomic_dec(&priv->active_tx_urbs);
+
+		if (err == -ENODEV)
+			netif_device_detach(netdev);
+		else
+			netdev_warn(netdev, "failed tx_urb %d\n", err);
+		stats->tx_dropped++;
+	} else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
 		/* Slow down tx path */
 		netif_stop_queue(netdev);
 
@@ -684,19 +695,6 @@ static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 
 	return NETDEV_TX_BUSY;
 
-failed:
-	can_free_echo_skb(netdev, context->echo_index, NULL);
-
-	usb_unanchor_urb(urb);
-	usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
-
-	atomic_dec(&priv->active_tx_urbs);
-
-	if (err == -ENODEV)
-		netif_device_detach(netdev);
-	else
-		netdev_warn(netdev, "failed tx_urb %d\n", err);
-
 nomembuf:
 	usb_free_urb(urb);
 
-- 
2.25.1