On Fri, 2016-10-21 at 19:02 +0800, f...@ikuai8.com wrote:
> From: Gao Feng <f...@ikuai8.com>
>
> Current tun driver permits the ifr_flags is set with IFF_TUN and
> IFF_TAP at the same time. But actually there is only IFF_TUN flag
> works. And it does not make sense these two flags are set, so add
> this check.
>
> Signed-off-by: Gao Feng <f...@ikuai8.com>
> ---
> v2: Remove useless {}
> v1: Initial patch
>
> drivers/net/tun.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index 8093e39..faaa189 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -1752,6 +1752,9 @@ static int tun_set_iff(struct net *net, struct file
> *file, struct ifreq *ifr)
> if (err < 0)
> return err;
>
> + if ((ifr->ifr_flags & (IFF_TUN | IFF_TAP)) == (IFF_TUN |
> IFF_TAP))
> + return -EINVAL;
> +
> /* Set dev type */
> if (ifr->ifr_flags & IFF_TUN) {
> /* TUN device */
This might break some applications.
It might be too late to add this check without a grace period.
