Patchwork [net-next,v2,1/3] can: mscan: fix improper return if dlc < 8 in start_xmit function

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Submitter Wolfgang Grandegger
Date Jan. 5, 2010, 7:19 p.m.
Message ID <1262719169-2350-2-git-send-email-wg@grandegger.com>
Download mbox | patch
Permalink /patch/42157/
State Superseded
Delegated to: David Miller
Headers show

Comments

Wolfgang Grandegger - Jan. 5, 2010, 7:19 p.m.
From: Wolfgang Grandegger <wg@denx.de>

The start_xmit function of the MSCAN Driver did return improperly if
the CAN dlc check failed (skb not freed and invalid return code). This
patch adds a proper check of the frame lenght and data size and returns
now correctly. Furthermore, a typo has been fixed.

Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
---
 drivers/net/can/mscan/mscan.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)
Wolfram Sang - Jan. 6, 2010, 2:33 p.m.
On Tue, Jan 05, 2010 at 08:19:27PM +0100, Wolfgang Grandegger wrote:
> From: Wolfgang Grandegger <wg@denx.de>
> 
> The start_xmit function of the MSCAN Driver did return improperly if
> the CAN dlc check failed (skb not freed and invalid return code). This
> patch adds a proper check of the frame lenght and data size and returns
> now correctly. Furthermore, a typo has been fixed.
> 
> Signed-off-by: Wolfgang Grandegger <wg@denx.de>
> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
> ---
>  drivers/net/can/mscan/mscan.c |   11 ++++++++---
>  1 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c
> index bb06dfb..7df950e 100644
> --- a/drivers/net/can/mscan/mscan.c
> +++ b/drivers/net/can/mscan/mscan.c
> @@ -4,7 +4,7 @@
>   * Copyright (C) 2005-2006 Andrey Volkov <avolkov@varma-el.com>,
>   *                         Varma Electronics Oy
>   * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
> - * Copytight (C) 2008-2009 Pengutronix <kernel@pengutronix.de>
> + * Copyright (C) 2008-2009 Pengutronix <kernel@pengutronix.de>
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the version 2 of the GNU General Public License
> @@ -177,8 +177,13 @@ static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
>  	int i, rtr, buf_id;
>  	u32 can_id;
>  
> -	if (frame->can_dlc > 8)
> -		return -EINVAL;
> +	if (skb->len != sizeof(*frame) || frame->can_dlc > 8) {
> +		dev_err(dev->dev.parent,
> +			"Dropping non-conform packet: len %u, can_dlc %u\n",
> +			skb->len, frame->can_dlc);
> +		kfree_skb(skb);
> +		return  NETDEV_TX_OK;

Double space.

> +	}
>  
>  	out_8(&regs->cantier, 0);
>  
> -- 
> 1.6.2.5
>

Patch

diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c
index bb06dfb..7df950e 100644
--- a/drivers/net/can/mscan/mscan.c
+++ b/drivers/net/can/mscan/mscan.c
@@ -4,7 +4,7 @@ 
  * Copyright (C) 2005-2006 Andrey Volkov <avolkov@varma-el.com>,
  *                         Varma Electronics Oy
  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
- * Copytight (C) 2008-2009 Pengutronix <kernel@pengutronix.de>
+ * Copyright (C) 2008-2009 Pengutronix <kernel@pengutronix.de>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the version 2 of the GNU General Public License
@@ -177,8 +177,13 @@  static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	int i, rtr, buf_id;
 	u32 can_id;
 
-	if (frame->can_dlc > 8)
-		return -EINVAL;
+	if (skb->len != sizeof(*frame) || frame->can_dlc > 8) {
+		dev_err(dev->dev.parent,
+			"Dropping non-conform packet: len %u, can_dlc %u\n",
+			skb->len, frame->can_dlc);
+		kfree_skb(skb);
+		return  NETDEV_TX_OK;
+	}
 
 	out_8(&regs->cantier, 0);