Re: [PATCH] [net/sched] Fix null pointer deref skb in tc_ctl_action

[David Miller]

From: Gaurav Singh <gaurav1086@xxxxxxxxx>
Date: Wed, 17 Jun 2020 21:43:28 -0400

> Add null check for skb
> 
> Signed-off-by: Gaurav Singh <gaurav1086@xxxxxxxxx>
> ---
>  net/sched/act_api.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/net/sched/act_api.c b/net/sched/act_api.c
> index 8ac7eb0a8309..fd584821d75a 100644
> --- a/net/sched/act_api.c
> +++ b/net/sched/act_api.c
> @@ -1473,9 +1473,12 @@ static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
>  static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
>  			 struct netlink_ext_ack *extack)
>  {
> +	if (!skb)
> +		return 0;
> +
>  	struct net *net = sock_net(skb->sk);

You're adding code before variable declarations, this is not correct.

I find your work to be very rushed and sloppy, please take your time
and submit well formed and tested changes.

Thank you.