From deb2701cf704a2fd03a8b598bf73df3edb08818d Mon Sep 17 00:00:00 2001 From: "Ahmed S. Darwish" Date: Thu, 26 Feb 2015 10:20:11 -0500 Subject: [PATCH] can: kvaser_usb: Avoid double free on URB submission failures Upon a URB submission failure, the driver calls usb_free_urb() but then manually frees the URB buffer by itself. Meanwhile usb_free_urb() has alredy freed out that transfer buffer since we're the only code path holding a reference to this URB. Remove two of such invalid manual free(). Signed-off-by: Ahmed S. Darwish Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- drivers/net/can/usb/kvaser_usb.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c index 2928f7003041..d986fe83c40d 100644 --- a/drivers/net/can/usb/kvaser_usb.c +++ b/drivers/net/can/usb/kvaser_usb.c @@ -787,7 +787,6 @@ static int kvaser_usb_simple_msg_async(struct kvaser_usb_net_priv *priv, netdev_err(netdev, "Error transmitting URB\n"); usb_unanchor_urb(urb); usb_free_urb(urb); - kfree(buf); return err; } @@ -1615,8 +1614,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb, struct urb *urb; void *buf; struct kvaser_msg *msg; - int i, err; - int ret = NETDEV_TX_OK; + int i, err, ret = NETDEV_TX_OK; u8 *msg_tx_can_flags = NULL; /* GCC */ if (can_dropped_invalid_skb(netdev, skb)) @@ -1634,7 +1632,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb, if (!buf) { stats->tx_dropped++; dev_kfree_skb(skb); - goto nobufmem; + goto freeurb; } msg = buf; @@ -1681,8 +1679,10 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb, /* This should never happen; it implies a flow control bug */ if (!context) { netdev_warn(netdev, "cannot find free context\n"); + + kfree(buf); ret = NETDEV_TX_BUSY; - goto releasebuf; + goto freeurb; } context->priv = priv; @@ -1719,16 +1719,12 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb, else netdev_warn(netdev, "Failed tx_urb %d\n", err); - goto releasebuf; + goto freeurb; } - usb_free_urb(urb); - - return NETDEV_TX_OK; + ret = NETDEV_TX_OK; -releasebuf: - kfree(buf); -nobufmem: +freeurb: usb_free_urb(urb); return ret; } -- 2.30.2