Re: [PATCH 1/2 nf] netfilter: nf_queue: don't re-enter same hook on packet reinjection

[Aaron Conole <aconole@bytheb.org>]

Pablo Neira Ayuso <pablo@netfilter.org> writes:

> Make sure we skip the current hook from where the packet was enqueued,
> otherwise the packets gets enqueued over and over again.
>
> Fixes: e3b37f11e6e4 ("netfilter: replace list_head with single linked list")
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> ---
> I managed to reproduce this with a simple test.
>
>  # iptables -I OUTPUT -j QUEUE
>  # cd libnetfilter_queue/utils/
>  # ./nfqnl_test
>
> Without my patch, netfilter munches packets that are reinjected.
>
> @Aaron: Please, I'd appreciate if you can have a look to confirm this bug
>         and the fix. Thanks.

Looks like I missed this in my testing.

Reviewed-by: Aaron Conole <aconole@bytheb.org>

>  net/netfilter/nf_queue.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
> index 96964a0070e1..221d7a5c2fec 100644
> --- a/net/netfilter/nf_queue.c
> +++ b/net/netfilter/nf_queue.c
> @@ -184,6 +184,7 @@ void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
>  			verdict = NF_DROP;
>  	}
>  
> +	hook_entry = rcu_dereference(hook_entry->next);
>  	entry->state.thresh = INT_MIN;
>  
>  	if (verdict == NF_ACCEPT) {