[PATCH 06/16] gtp: add error handling to gtp_newlink

[Pablo Neira Ayuso]

On Mon, Nov 16, 2015 at 04:06:47PM +0100, Andreas Schultz wrote:
> Signed-off-by: Andreas Schultz <aschultz at tpip.net>
> ---
>  gtp.c | 32 +++++++++++++++++++++++---------
>  1 file changed, 23 insertions(+), 9 deletions(-)
> 
> diff --git a/gtp.c b/gtp.c
> index 11f8fad..4f5729e 100644
> --- a/gtp.c
> +++ b/gtp.c
> @@ -756,8 +756,12 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev,
>  
>  	if (!tb[IFLA_MTU])
>  		dev->mtu = real_dev->mtu;
> -	else if (dev->mtu > real_dev->mtu)
> -		return -EINVAL;
> +	else if (dev->mtu > real_dev->mtu) {
> +		netdev_dbg(dev, "GTP mtu greater that transport MTU (%d > %d)\n",
> +			   dev->mtu, real_dev->mtu);
> +		err = -EINVAL;
> +		goto out_err;

This is function is using __dev_get_by_index(), so we're not holding a
reference on the netdevice here.

> +	}
>  
>  	gti = netdev_priv(dev);
>  	gti->real_dev = real_dev;
[...]
> +out_err:
> +	dev_put(real_dev);
>  	return err;
>  }