+ Xin Long <lucien.xin@xxxxxxxxx>
Aaron Conole <aconole@xxxxxxxxxx>
coreteam@xxxxxxxxxxxxx
On Fri, Dec 22, 2023 at 11:43:11AM +1300, Brad Cowie wrote:
> This fixes openvswitch's handling of nat packets in the related state.
>
> In nf_ct_nat_execute(), which is called from nf_ct_nat(), ICMP/ICMPv6
> packets in the IP_CT_RELATED or IP_CT_RELATED_REPLY state, which have
> not been dropped, will follow the goto, however the placement of the
> goto label means that updating the action bit field will be bypassed.
>
> This causes ovs_nat_update_key() to not be called from ovs_ct_nat()
> which means the openvswitch match key for the ICMP/ICMPv6 packet is not
> updated and the pre-nat value will be retained for the key, which will
> result in the wrong openflow rule being matched for that packet.
>
> Move the goto label above where the action bit field is being set so
> that it is updated in all cases where the packet is accepted.
>
> Fixes: ebddb1404900 ("net: move the nat function to nf_nat_ovs for ovs and tc")
> Signed-off-by: Brad Cowie <brad@xxxxxxxxx>
Thanks Brad,
I agree with your analysis and that the problem appears to
have been introduced by the cited commit.
I am curious to know what use case triggers this /
why it when unnoticed for a year.
But in any case, this fix looks good to me.
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
> ---
> net/netfilter/nf_nat_ovs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/netfilter/nf_nat_ovs.c b/net/netfilter/nf_nat_ovs.c
> index 551abd2da614..0f9a559f6207 100644
> --- a/net/netfilter/nf_nat_ovs.c
> +++ b/net/netfilter/nf_nat_ovs.c
> @@ -75,9 +75,10 @@ static int nf_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
> }
>
> err = nf_nat_packet(ct, ctinfo, hooknum, skb);
> +out:
> if (err == NF_ACCEPT)
> *action |= BIT(maniptype);
> -out:
> +
> return err;
> }
>
> --
> 2.34.1
>
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