Re: [PATCH] openvswitch: add sanity check in queue_userspace_packet.

[Pravin Shelar]

On Mon, Nov 28, 2016 at 8:36 PM, Haishuang Yan
<yanhaishuang@xxxxxxxxxxxxxxxxxxxx> wrote:
> kernel will crash in oops if genlmsg_put return NULL,
> so add the sanity check.
>
> Signed-off-by: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>
> ---
>  net/openvswitch/datapath.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index 2d4c4d3..ceb1b1e 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -474,6 +474,10 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
>
>         upcall = genlmsg_put(user_skb, 0, 0, &dp_packet_genl_family,
>                              0, upcall_info->cmd);
> +       if (!upcall) {
> +               err = -EMSGSIZE;
> +               goto out;
> +       }

user_skb has already enough space allocated, so there is no need to
check upcall pointer.