Subject: Re: [Patch net-next] net_sched: fix suspicious RCU usage in cls_bpf_classify()

From: John Fastabend <[email-masked]>
Date: Mon, 15 Sep 2014 14:30:19 -0700

On 09/15/2014 02:21 PM, Cong Wang wrote:
> Fixes: commit 1f947bf151e90ec0baad2948 ("net: sched: rcu'ify cls_bpf")
> Cc: John Fastabend <[email-masked]>
> Signed-off-by: Cong Wang <[email-masked]>
> ---
>  net/sched/cls_bpf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
> index 6a7386e..4e3f5bf 100644
> --- a/net/sched/cls_bpf.c
> +++ b/net/sched/cls_bpf.c
> @@ -52,7 +52,7 @@ static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
>  static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
>  			    struct tcf_result *res)
>  {
> -	struct cls_bpf_head *head = rcu_dereference(tp->root);
> +	struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
>  	struct cls_bpf_prog *prog;
>  	int ret;
>  
> 

you beat me to it.

Acked-by: John Fastabend <[email-masked]>