| Message ID | 20130913122927.GA31819@elgon.mountain |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, 2013-09-13 at 15:29 +0300, Dan Carpenter wrote: > If new_mtu is very large then "new_mtu + ETH_HLEN + ETH_FCS_LEN" can > wrap and the check on the next line can underflow. This is one of > those > bugs which can be triggered by the user if you have namespaces > configured. > > Also since this is something the user can trigger then we don't want > to > have dev_err() message. > > This is a static checker fix and I'm not sure what the impact is. > --- > v2: reformat and also remove the dev_err() > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Thanks Dan, I have added your patch to my queue.
diff --git a/drivers/net/ethernet/intel/igbvf/netdev.c b/drivers/net/ethernet/intel/igbvf/netdev.c index 95d5430..8cb7958 100644 --- a/drivers/net/ethernet/intel/igbvf/netdev.c +++ b/drivers/net/ethernet/intel/igbvf/netdev.c @@ -2344,10 +2344,9 @@ static int igbvf_change_mtu(struct net_device *netdev, int new_mtu) struct igbvf_adapter *adapter = netdev_priv(netdev); int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN; - if ((new_mtu < 68) || (max_frame > MAX_JUMBO_FRAME_SIZE)) { - dev_err(&adapter->pdev->dev, "Invalid MTU setting\n"); + if (new_mtu < 68 || new_mtu > INT_MAX - ETH_HLEN - ETH_FCS_LEN || + max_frame > MAX_JUMBO_FRAME_SIZE) return -EINVAL; - } #define MAX_STD_JUMBO_FRAME_SIZE 9234 if (max_frame > MAX_STD_JUMBO_FRAME_SIZE) {
If new_mtu is very large then "new_mtu + ETH_HLEN + ETH_FCS_LEN" can wrap and the check on the next line can underflow. This is one of those bugs which can be triggered by the user if you have namespaces configured. Also since this is something the user can trigger then we don't want to have dev_err() message. This is a static checker fix and I'm not sure what the impact is. --- v2: reformat and also remove the dev_err() Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html