Re: WARNING in __rcu_read_unlock

[Dmitry Vyukov]

On Mon, Dec 17, 2018 at 4:24 PM Stefano Brivio <sbrivio@xxxxxxxxxx> wrote:
>
> On Mon, 17 Dec 2018 06:57:35 -0800
> Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote:
>
> > Might be cause by commit b8a51b38e4d4dec3e379d52c0fe1a66827f7cf1e
> > fou, fou6: ICMP error handlers for FoU and GUE
>
> This:
>
> diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
> index 0d0ad19ecb87..20a6de26d146 100644
> --- a/net/ipv4/fou.c
> +++ b/net/ipv4/fou.c
> @@ -1008,6 +1008,9 @@ static int gue_err_proto_handler(int proto, struct sk_buff *skb, u32 info)
>  {
>         const struct net_protocol *ipprot = rcu_dereference(inet_protos[proto]);
>
> +       if (ipprot == IPPROTO_UDP)
> +               return -EINVAL;
> +
>         if (ipprot && ipprot->err_handler) {
>                 if (!ipprot->err_handler(skb, info))
>                         return 0;
>
> should fix the issue, but I still have to run tests and make sure we
> don't hit similar cases.

Please don't forget to add a regression test for it too ;)