can: mscan: fix improper return if dlc < 8 in start_xmit function

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. The invalid skb packets are dropped silently as suggested
by David Miller in the thread "[RFC] ndo_validate_skb: Let the netdev
check a valid skb content" on the netdev mailing list.

Furthermore, a typo has been fixed.

Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wolfgang Grandegger 2010-01-07 09:43:06 +00:00 committed by David S. Miller
parent 5856b606e6
commit 2d4b6faf7d
1 changed files with 6 additions and 3 deletions

View File

@ -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 +177,11 @@ 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) {
kfree_skb(skb);
dev->stats.tx_dropped++;
return NETDEV_TX_OK;
}
out_8(&regs->cantier, 0);