From: Subash Abhinov Kasiviswanathan <subas...@codeaurora.org>
Date: Tue, 21 Mar 2017 21:20:10 -0600
> @@ -329,7 +329,7 @@ static int ip_rcv_finish(struct net *net, struct sock
> *sk, struct sk_buff *skb)
> int protocol = iph->protocol;
>
> ipprot = rcu_dereference(inet_protos[protocol]);
> - if (ipprot && ipprot->early_demux) {
> + if (ipprot && READ_ONCE(ipprot->early_demux)) {
> ipprot->early_demux(skb);
I think you need to use a local variable for the function pointer in conjunction
with READ_ONCE() for this to work properly:
if (ipprot && (func = READ_ONCE(ipprot->early_demux))) {
func(skb);
...
> diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
> index aacfb4b..30d18cb 100644
> --- a/net/ipv6/ip6_input.c
> +++ b/net/ipv6/ip6_input.c
> @@ -60,7 +60,7 @@ int ip6_rcv_finish(struct net *net, struct sock *sk, struct
> sk_buff *skb)
> const struct inet6_protocol *ipprot;
>
> ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
> - if (ipprot && ipprot->early_demux)
> + if (ipprot && READ_ONCE(ipprot->early_demux))
> ipprot->early_demux(skb);
> }
> if (!skb_valid_dst(skb))
Likewise.
